I don’t feel like I’m an expert on breakbeats, but what I can say about general beat making is that getting a feel for the rhythm is obviously very, very important, especially if you’re using a step sequencer.
In either case, you want to put your main kick and snare pattern together, and build around that with other percussion (cymbals, toms, random noise, whatever). You’ll also want to include different velocities or utilize accents if you can, and even ghost notes. If your sequencer allows, try including some micro-timing of certain hits too to kind of keep things just a little off-kilter.
You can also use a mix of sequences and sampled sounds and loops, so maybe your main kick and snare is sequenced, but you’ve got a good high hat or percussion loop over that.
I’d also say that once you have your main 16 or 32 step pattern, create as many variations of that as you can, even if they just include one or two extra hits, or a snare roll, or something like that. Then you can chain those together to keep things interesting, or even include chance/random hits throughout your beat if your sequencer allows.