There is a combo that I've been using lately; it's definitely not a true combo (i think) but it works often and when it does it's hella sweet, literally.
Fthrow into up smash, if you do it correctly/time it right then you'll hit them in usmash's sweetspot. This is a lot easier to do in earlier percentages but it is doable in higher percentages as well, I've even used it as a kill move before when people expect a fair string after the fthrow and either DI away from/near sheik or air dodge instantly, if you get right underneath them and do an up smash it'll often sweetspot and the sensation of getting it is literally sweet.
I haven't looked at it in-depth but I trust amazing people like @
Tristan_win
and other 'researchers' to test it out!
sorry for the lack of videos but I just got my WiiU and it doesn't have an SD card so I can't save replays lol