Well as of now I switch between my mains and secondaries in this order:
MK, Toon Link, Sonic, Marth, Lucario
I think I'm getting worse with Marth sadly, That might have been when I experimented around with other characters like Snake and Toon Link (It took me a few matches after using Snake for a day to get back to using Meta Knight XD).
My Toon Link skills have gotten better (not up to par with most of the TL players here, but it's getting good), and for some reason I've been getting more 1v1 matches on 'with anyone.' So far I've won those with Meta Knight (I had already played 1v1 Friend matches online and offline with him), Toon Link, and Sonic (but only once with him.)
Again if the group I am playing with is pretty bad I will just pick random, but I stopped picking Ganondorf as my Last battle Character.