samus upb
mario dair > uair
luigi dair > aerial > upb
ness uairs/dairs/a lot of things
etc
a lot of characters have fairly easy shield break tactics, the hard part is getting the opponent in the right place to shield.
imo yoshi is harder to shield break than ness because yoshi requires timing of sorts whereas ness can just go as fast he wants. more precisely, with ness i do the whole: 'slide my thumb from left c to down c to a, but trying to do that with yoshi results in him going way to fast. i find with yoshi it's best just to hit down c twice and do that as fast you can.