Does anyone have any tips for using Link's F-smash? I use all of his other moves except that because I've always felt it to be too slow since the second hit is the one where all the power really is and it takes awhile to actually come out as a hit box. Any ideas or uses for it?
I'm a little late, but I actually use this move quite frequently [but rarely ftilt].
The move is like 2 frames slower than ftilt, but it's generally respected more as long as you don't always do the second slash. Against aerial spacies at low percents both hits can connect for like 30% [and they often have to tech or wiggle out of hitstun or land with an aerial, which is punishable], so if you want to call out a spacie shorthop it's a good move. Bomb -> fsmash at low percents on airborne spacies is awesome. Here's a sequence where I throw a bomb to bait a jump out of shield [to avoid grab], then fsmash to catch his jump - I'm able to then land more damage after that and ultimately convert it to a stock (although DI could have been better, the principle is still on display:
http://gfycat.com/JoyfulThornyIrishterrier ).
Fsmash is also useful to punish anything rather slow - for instance, if you force Falcon off the stage at low percents and grab ledge while he can recover onstage and he does so, you can probably ledgedash fsmash, and if he tries to CC it he's in prime position for both hits. Another great example is when you hit a character with bad airspeed [for instance, Marth] with a boomerang when they jumped - they now need to land, where they can double jump, fair, dair, side+B, or land with nothing. The latter two are covered by well-spaced usmash, while shieding beats fair, dair, and side+b up close and jump leaves him in prime position to be juggled. If you think he's just going to land, fsmash is often a great punish
It's also a mixup on shield, since if you don't do the second hit right away, they can wait it out or jump or wavedash - it's hard to react to, but if you get it right, you get a solid blow and a nice chunk of damage. You can also sometimes fsmash after a zair or a grab [uthrow or dthrow if they don't tech or fall in range, usually has to be a read on those things though].
Here's a video of me fighting a Fox player - I definitely have a lot to work on, and I admit I fsmash more than I should, but it has the boomerang -> fsmash and some other times I use it. I probably have better moves to be using, but it can maybe give you an idea of where to put fsmash into your game:
https://www.youtube.com/watch?v=emcAJxAQgwM
