I have one more for you. Say you are diving in with your right (inside) hand and shoulder (so you start with his right leg in your 1/2-guard, and your left leg as a shield). Follow your shield into a tight, non-shield 1/2-guard with a deep outside (left) underhook. Take your left (outside) leg first, and hook it over and behind the guy's right leg at the ankle, kinda like a one-leg lockdown. Use that hook the "open" his leg by pulling his foot outside (to your left) with your foot. This will extend his leg the wrong way, just like a lockdown, and his weight will drop forward and to your outside (left). Once you are comfortable with this, start diving into deep as his weight shifts (so at the same time as you open his leg). You combine "moving you" AND "opening him up" because it is very hard to stay heavy while someone opens your leg like that. Even if you only get halfway, you can keep using that leg grip to wiggle your way in there. Also, you usually end up with his whole leg trapped in your deep guard, rather than just his ankle, which opens up some other really cool sweeps that aren't as mainstream.