I don't like the pushing away of the head, obvious what you are doing, besides, just not pretty. If you have ever done that armbar drill where you spin underneath and armbar, left, right, left, right....I do the same motion. Just swing your leg up and spin on your back, actually you will want to swing up both legs somewhat, but emphasis on the "locking" leg. As an alternative, say I have a triangle and he is posturing and muscling out of it, reach between his legs and pull yourself back and to the side that his trapped arm is on, just like reaching under for an armbar but pull your head all the way to his knee. One more note: I personally find the best way to get in omoplata position no gi, is not to work an arm to the side, push the head, yadayadayada....but just throw up a crappy triangle, not even aiming for the triangle, unless he's oblivious to my obvious sub attempt, and as long as his head and arm is between my legs, plata.
