This is probably old hat:
Corner ground hk throw into s.lp+Storm s.hk (one hit) xx MT - works on Cable, Capcom, Psylocke, Cyke, etc., pretty tough on Magneto, pretty much impossible on Storm
ROM into corner (put them low), land, s.lp+Storm s.mk xx MT
OR
ROM into corner (put them low), land, s.lp+Storm s.mk HG xx MT (exceedingly hard to mash and gets you more hits than the previous setup) - both of these work on Storm, Psylocke, Capcom, NOT Cable, maybe Mag