We've both played Sheik, and I don't agree with Sheik needing to put as much effort. Sure, she needs effort to play well, but she still has guaranteed combos and 50/50 situations. One big tip for playing against Yoshi is to shield, especially at higher percents. The only thing that Yoshi can kill you when you shield is a down-B, and that is easily predicted. Neutral B only allows for damage and has no kill set-ups because you can always jump and air dodge out, and the same goes for his throws. Never jump right away when Yoshi forward throws. Other than that, you shouldn't be afraid to shield against Yoshi.
I saw some guy have his tag as "LessRolls" for his previous opponent. That seems like a nicer way to put it, and when I thought he was going to be a nice opponent when I saw that.
Ha when Sheik has to individually hit you twice as much or more for the kill, she's working. Some of that is guaranteed (more at lower percents), but so is everyone else's at low percents. I mean, even Bowser has a close to guaranteed uair to fair at 0%. I don't mean to be the Sheik defense force here though. For Yoshi, I'd be happy to stay in shield but I'd just get peppered with eggs or spaced fairs until the situation becomes untenable. Of course there are exceptions, but I ran across a pretty good Yoshi in FG the other day who put me in the dilemma I described. Of course I didn't save a replay :/
Edit: forgot to mention I'm going to steal the "LessRolls" profile. Maybe I'll make a couple others too.
I should follow your example Cronox and just leave when I don't like the opponent I am fighting. Little Mac is so annoying.
Little Mac is super annoying when played well. I played a LM for an hour or so the other night just camping the ledge work-shopping how I could gimp him off a back throw. The fucker was nearly ungimpable. I think I managed it twice in more than a dozen matches. I don't want to fight a Mac that passes the for glory test (back throw -> fairX2) for real, it's just discouraging. Almost makes me wish charging smashes wasn't a thing.
Edit: what the hell is with FG lately, it's filled with almost nothing but people playing characters I don't like or I'm sick of playing against. I leave a Little Mac, there's another Little Mac. Another Ganondorf. A... Marth? Oh wait, he went Ganondorf after I beat him the first time. Gah... I did have one good match against a good Little Mac, I generally camped the ledge and he generally refused to approach. Finally went aggro and killed him with under 30 seconds left. After that the guy switched to... Ganondorf.