I do something similar, but I tack on an 8-interval core sequence at the end. My current sequence: leg lift, russian twist, reverse crunch, crunch, bridge, superdog, side crunch, side crunch.

Or if a pushup/pullup is your goal, I'm a huge fan of the assisted pullup/progressive pushup. (Caveat: I still can't do either.) When I still had access to a gym, I used the smith machine to work on my pushup.