Advice from Alex

Don't waste energy defending (being passive), keep attacking, it's the same amount of energy but it keeps your opponent's weight off you.

For the leg that needs to shoot up for a triangle, PIN IT DOWN! Overhook like Sam showed and pin the leg down so your opponent doesn't kick it up for the triangle.

Why Not To Cross Your Hooks When You Have Back Control

Skip to 1:30 for the submission.