Heres how I destroy ikes.
Things to watch out for: Fsmash, Usmash, bair, dash attack
When an Ike sees a jigglypuff, they laugh. When I see an Ike, I laugh. Ikes are powerful, sure but they get tossed around like a ping pong ball. Them being heavy is a HUGE disadvantage for them. Theres nothing I love more then to lay down insane combos on Ikes in midair.
If you see an Ike standing there charging his F smash and your not near him, you should take advantage of this. Ikes do this to jigglypuffs because jigglypuffs have to play very very aggressive play style. They are always in their face and Ike just wants to swat us away. He can kill us at VERY low percentages.
If an Ike is just camping; charging his Fsmash or any type of move that requires charging start charging up your rollout. Now its just a stare down. Who will let go first. Of course Ike will .Since rollout can be infinitely charged use this to your advantage. As soon as ike finishes his huge laggy attack come for the rollout and follow up with everything you've got possibly a Dair to rest. (Ike - 77%)
If your infront of an ike and he starts charging his Up smash. RUN AWAY. Run far far away. Don't even try to hit him before he lets it out. If you roll behind him the up smash will reach you and you will die.
Pound is your friend. Use it for coming back on stage. and DO NOT run into his smashs. Its so tempting to just cancel his smash but its not worth playing it so risky. Just wait for his smash to end and come in with anything you want. You have plenty of time.
As for recovery. Ikes may use their side b to get back on stage. If your at a low percentage jump right infront of this if its not close to the stage. He falls to his death (sort of like how your rollout kills you if you hit someone on the way to the stage) and if you get spiked by his up-b don't sweat it. you have a great chance of recovering even if your all the way off the stage. Jigglypuff can make it back from pretty much anywhere if you have all your puffs in you.