My warm up each morning starts with 100 stability (Swiss) ball crunches.  I do these – not for my abs – but to loosen up my back.  Really need to warm up the back to get me standing straight and ready to work-out.

I have been sliding from that position into a Stability Ball Pelvic Thrust.  Here is a picture of it.  The only difference – I have my hands behind my head and am just a bit further down on the ball. I sink my pelvis down and then thrust upward – tightening everything. I hold that position – almost like a reverse plank – for as long as I can. Try it.