From a
YouTube video by Adem Redzovic . .
1. Open your guard. Don't let it be opened. Control the transition so you control the timing.
2. Maintain as many points of contact as possible, ideally 4. These will be hands & feet ideally, but even hands and knees will be better than no leg involvement.
3. There are 3 lines of defense in a battle of guard retention. Feet, knees, and then your body position.
4. Reset when necessary. In a similar vein to #1, control the transitions so you control the position. If you are in a bad position, move to a better one even if it is the one you started in. A reset is better than being smashed and passed.