Now this is somewhat situational, but one thing I like to do with Crash Bomb is to catch them with it as they get up from the edge or stand near it, with MM positioned a little over roll distance from the edge. They'll either shield or roll, and you should have plenty of time to grab, preferably pivot grab if possible, and throw up for lower percentages, or down for higher. I haven't quite figured out a sure-fire way to know who the bomb will stick to, but know this: if it sticks to MM, give chase without expending your double jump and evade as the bomb explodes. Knowing your 3-second time limit is crucial for this.
I know that this move is not going to happen all that often and could be labeled somewhat unreliable.....I just wanted to contribute something I do that has worked to set up aerials.
Also, have you tried sticking the bomb to the edge of FDs with walls running down? Makes for some interesting recoveries.
Eh....these aren't all that great....ah well. I'm not good at this whole guide thing. Better Mega Men will give you far better input.