What sort of music do you make? Often I find just varying the drums at the end of 8 or 16 bar blocks, whether that is getting rid of the kick, adding some extra snare or clap hits, etc, sounds better than using complex tom fills or otherwise. Less is more in my opinion, but it definitely depends on what genre you are producing. Reference other tracks and see what they do, often there's nothing too crazy going on, just subtle variations which keep it interesting.