Low mount: if the guy manages to move your hips lower, gets his elbows in tight against his body, etc. then the low mount is another option. Keep the knees wide and lock the hooks under his legs. Put a shoulder into his face to direct him to one side, and put the arm on that side outstretched for balance. I'd imagine that it is a little easier to attack the arms from a somewhat lower mount ...
From the Abaya Academy.
Miscellaneous notes: swim arms in one at a time if the guy tries to bench press you (and you're not in position to armbar him). Swim the arms under to break the grip.
If the guy presses down on your hips, then reach down and grab the arm at the wrist and pull up sharply. As you do that, replace your leg higher up under his arm.
