Jigglypuff has a unique playstyle unlike any other character in Smash. With her multiple jumps, fast air speed, and powerful aerial attacks, Puff is an air fighter through and through--essentially the opposite of Little Mac. Jigglypuff is well-known for her "rest" attack, which is one of the strongest moves in the game.
Jigglypuff has several weaknesses though. Mainly, she is the lightest character in the game, so she dies really easily. Puff also dies immediately if her shield breaks. Puff can also struggle against sword characters with their large disjointed hitboxes, as well as against projectiles that move up into the air, such as the Belmonts' axe.
The general strategy that you want to utilize is to float around outside of your opponent's range while constantly throwing out attacks, and then weave in and hit them with an attack when you see an opening. The long lasting hitboxes on your nuetral air and forward air will hit anyone who trys to rush in and attack you carelessly.
You get 6 total jumps (1 grounded jump and 5 mid-air jumps), and it's a good idea to get in the habit of counting them as you use them, so you don't end up off stage without enough jumps to recover. In general, from out in the side blast zone, you will need 3 jumps to recover if you are below the ledge, but two should be enough if you are above the ledge.
Puff is fast and mobile in the air, and slow on the ground, so you don't really want to spend much time on the ground. You also want to avoid using shield as much as possible, especially when fighting opponents who have attacks that do large damage to your shield. Rather than standing around on the ground and shielding, stay in the air and use your jumps to dodge your opponent's attacks, and air dodge if absolutely necessary.
At low percents, there are some short combos that you can use to rack up some damage, and then at mid percents you can look to start trying to kill your opponent off of a combo into rest, or by taking them offstage and gimping their recovery. Puff is one of the best edge-guarders in the game. If your opponent manages to make it to higher percents without dying, you can usually kill them with a back aerial or a forward smash.
Jab: A basic jab, can hit twice for about 7% damage and knocks the opponent away.
Up tilt: Hits behind you for 11% and knocks the opponent into the air. This can lead to combos and followups. A good attack if the opponent crosses you up, or if you cross your opponent up.
Forward tilt: It's an okay forward tilt that does 12% and can be angled up and down. Be careful using this at low percents because this doesn't knock the opponent very far away which might leave you open to a counterattack.
Down tilt: Also does 12% but comes out slightly slower than the forward tilt. This move knocks the opponent away from you even at low percents, and after about 20%-30% it will knock the opponent down.
Up smash: Not your best smash attack. Does 18% damage but you will struggle to kill the opponent with this. Even from the top platform of battlefield, side smash will kill before this does.
Side smash: Your best smash attack for killing, if you get the opponent to high percents. Does 16% damage.
Down smash: This is top tier when it comes to style. Charging this move up is like a taunt in itself. Other than that, it only does 11% damage and doesn't kill easily. You do get invincibility on your feet though, making it a good option for catching the 2-frame when your opponent grabs the ledge. This also hits on both sides.
Neutral aerial: This is your fastest aerial to come out, does 11% damage, and has a really long lasting hitbox. Great move for edge-guarding!
Up aerial: Knocks the opponent upwards for 9%. Falling up aerial (hit the opponent just before you land on the ground) is one of your primary combo starters and your best rest setup.
Forward aerial: Great attack which does 9% and has a fairly long lasting hitbox. One of your primary tools as Jigglypuff. At medium percents, forward aerial will start knocking the opponent down, allowing you to quickly follow up with another one as they hit the ground. If you hit the opponent off the stage with this, you can sometimes keep hitting them with 2 or 3 more in a row, taking them out into the blastzone.
Back aerial: Your strongest aerial attack, doing 13%, and one of your best kill moves at higher percents.
Down aerial: A good multi-hit move that can combo into rest at almost any percent (though not reliably). The final hit of this move will knock your opponent far away from you, so you generally want to fast fall into the ground while using this to keep the last hit from coming out.
Neutral special - Rollout: Charge it up and then release to roll into your opponent at high speed. While this is a powerful move, don't expect it to work against experienced opponents, because it is very easy to dodge. You also run a risk of rolling off the stage to your death. I recommend avoiding using this move in any serious match. This can break shield if you roll into a shielding opponent and then turn around and roll back into them again.
Up special - Sing: Jigglypuff will sing, sending waves out from her body that will put the opponent to sleep. In previous smash games, this move was fairly useless, but its actually a pretty good move now! If you hit your opponent with this, you should have time to either hit them with a smash attack or a rest. This can be quite effective at catching an opponent's landing if they aren't expecting it. This move does leave you open to a counter attack though, so don't just throw it out randomly.
Side special - Pound: Punches the opponent and knocks them up into the air. Also does massive shield damage. Use this if your opponent is shielding a lot and you might be able to break their shield, setting up for a rest or smash attack. This attack also stops your aerial momentum, which might be good for confusing the opponent when you are trying to land. This move can also extend your horizontal range when trying to recover to the stage.
Down special - Rest: The move that defines Jigglypuff. This move does massive damage to the opponent and can kill fairly early. If it doesn't kill, it plants a flower on their head which will continue to do even more damage over time. However, this move is very difficult to hit with, and using it puts Jigglypuff to sleep for several seconds, leaving her wide open to attack. There is a whole section about this move below.
Throws: Jigglypuff generally doesn't have any followups out of her throws. They should just be used for damage or stage control. Her pummel is also pretty weak (1.5%) but comes out fast.
Up throw: Pretty much useless. Doesn't do much damage, and can't kill until really high percents.
Forward/back throw: These are useful for positioning or tossing the opponent off stage. They both do 12%.
Down throw: Your most damaging throw, doing 14%.
Note: all percentages given will vary slightly depending on your opponent.
The following combos work starting from 0% unless otherwise noted
Falling up aerial, up tilt, up aerial = 27% damage
Only use this when the opponent is at 0%. After the opponent is damaged, the uptilt will likely miss.
Up tilt, up tilt, up aerial = 27% damage
Only use this when the opponent is at 0%. After the opponent is damaged, the 2nd up tilt will likely miss.
Up tilt, up aerial = 20% damage
Works until the opponent is around 40%.
Falling forward aerial, forward tilt= 22% damage
Can work until about 30%, but gets more difficult the higher the percent is. You might be able to follow up with a grab at lower percents, but it is not guaranteed.
Falling forward air, down tilt = 22% damage
Similar to the above combo, but knocks the opponent further away from you, making it safer.
Falling forward aerial, grab, down throw = 25% damage
Works until about 20%.
Falling up aerial, up aerial = 20% damage
Starts working around 30% until about 60%.
Ths is Jigglypuff's signature move, and one of the most powerful techniques in the game. But if you miss, you wil be completely vulnerable for several seconds. This hit box is within jigglypuffs body, so in order to hit your opponent, you have to actually overlap with them somehow, such as by jumping into them, and then use the move with perfect timing. Since Smash Ultimate made it so that you can no longer run through your opponent, jumping at them is the most effective way to overlap. You can also use this to catch an opponents roll as well. You generally aren't going to be trying to hit the opponent with this move in neutral, but rather you will usually try to combo into it. You also don't want to use it off-stage because you will fall to your death.
Rest KO percents:
Here are the basic KO percents that you should memorize to know when a rest will kill your opponent. These percents are quite conservative to account for stage selection, DI, and other factors. So you might actually be able to kill sooner, but I consider these "safe" percents to guarantee a kill.
Light weights: 50%
Medium weights: 60%
Heavy weights: 70%
Falling up aerial into rest:
Falling up aerial into rest is your primary rest combo. It is easy to land on any opponent and kills at medium percents.
Here are the percentage ranges that it can generally KO at (Again, these percentages are fairly conservative):
Light weights: 40-60%
Medium weights: 50-70%
Heavy weights: 60-80%
Down aerial into rest:
Down aerial to rest can combo at just about any percent, but its not entirely reliable because the down aerial might hit the opponent out to the side. If the final hit of the down air connects, then it will knock the opponent far away, so you need to fastfall so you land before the final hit connects. The easiest way to to this is to just jump, then start fastfalling at the peak of your jump and then immediately do the down air, then start mashing down-b so it will come out as soon as the down aerial ends. With some practice you should be able to get it to connect fairly consistently, but its up to you if you want to take the gamble in a real game. Some people say that it is more reliable if you jump backwards towards the opponent while doing the down aerial, but I haven't seen any noticable difference in effectiveness.
On Battlefield, full hop and then air dodge downward to land on the lower platforms quickly. Full hop twice then air dodge downward to land on the upper platform. From the ground, your full hop aerials can hit opponents on the lower platforms. A double full hop aerial will hit opponents on the upper platform.
This also works on Pokemon Stadium 1, but most other stages will require an additional jump to reach the platforms.
With Jigglypuff, you can turn around anytime you use one of your midair jumps. This can be useful to turn around in order to use a back air. To do it, simply press the control stick in the opposite direction that you are moving and jump, then press the control stick back in the original direction that you were moving. Note that this does stop your momentum. Another way of turning around in midair is to simply do a back aerial--this will turn you around without losing momentum.
Jigglypuff should probably always use a fox-trot rather than dashing on the ground. A fox-trot is done simply by starting to dash, then releasing the control stick and starting a dash again while your character is still in the dash start-up animation. So if you want to run to the right, you would basically just press right repeatedly, not too fast, not too slow. Fox-trotting is important for Jigglypuff to be able to do the reverse aerial rush.
Reverse Aerial Rush:
This technique is used to do a back aerial while running towards the opponent. For most characters, you would execute this by dashing, then pressing the control stick in the opposite direction, and then jumping to cancel the turnaround animation.
However, Jigglypuff gets the short end of the stick here. That's because Jigglypuff can't really do a reverse aerial rush out of her dash without frame-perfect timing. You can do it out of a fox-trot though! Basically, this works out of fox-trot, out of an initial dash animation, while walking, or while standing. This is an extremely important technique when your opponent gets to higher percents and you are trying to hit a back air for the KO.