Here are some great guard retention concepts from BJJ black belt Samir Seif:
There are 7 layers before your guard is passed.In this video i address the three layers of the legs being passed,and the check point of your hips are in jeopardy.The next 4 layers are your arms.I break it down with the Island Top Team.
Frame and hip escape
elbow collar tie up
reverse collar tie up
These will lead to constant guard retention without fearing that your hips have been passed.
Andre Galvao also offers some great insight:
Learn the secrets of creating an impenetrable guard or framing to stop your opponent’s guard from BJJ star, Tom DeBlass.
Recruit framing and guard retention concepts that will add enhanced security and effectiveness to your bottom and top game.