Yoshi
Ignore everything from YoshiDinoBroYo Do not use random moves, this is never a good idea. The egg will not fall off the stage if you use egg lay by the ledge unless your fighting a CPU opponent or someone who has never played smash before. Moving the control stick toward the stage if you are stuck in an egg will cause the egg to land on the stage. Up-smash is a great kill move but ...

SSB4: Yoshi - Egg Roll
The best use for this move I've found is baiting out counters from FE characters + shulk, lucario, little mac etc. Most people will attempt to counter it as soon as you roll up. Press B to cancel it right before you hit them and they will probably counter, you can then hit them with whatever you want. Mix it up the next time, plow right through them because they probably wont counter and expect ...

SSB4 with characters: [u'Ganondorf', u'Mewtwo']
A good mewtwo should be able to beat a good ganondorf without being hit. Mewtwo beats him on range and speed. Even though a good ganondorf could take out mewtwo in 2 hits. A Good mewtwo could play it safe enough to beat him.