I personally am very grab centric in general, and with Roy having the second largest grab disjoint in the game, it's a pretty good compliment to my game. I'm a firm believer that varying the way your movement looks is huge, so I constantly mix up my DD patterns, and throw in empty SHs and tomahawks that sit on the edge of the opponents punish range. Throughout my dds, I'll litter in dtilts to threaten space and encourage the opponent to respect it.
Another thing I'm a big fan of is empty pivots during DDing. Its something a lot of melee players aren't used to, and it can throw of your opponents projected idea of what space you'll be moving in. Pivot dtilts, ftilts, side bs, jabs, grabs,and fsmashes are great, and can snag your opponent unexpectedly when they weren't planning to crouch (since a lot of those moves are beat by ccing).
Side b is a great anti air tool, and can be used on the run, during pivots, and even continued to provide additional coverage. Also his second fastest move.
Dtilt is dtilt, lol.
That's a pretty good synopsis of my mindset during neutral