Couple points
Understand traditional "high" posture inside closed guard as well as good "low" or "safety" posture inside closed guard. Safety posture is inside control of biceps, head in middle of chest, stay tight.
The idea is to build up a base from safety posture to high posture. From high posture you throw your bombs and immediately reset to low posture, then build up again.
Also, your armbar anticipation, sensitivity, and counters should be very good. Anticipating an armbar in reaction to your punch then countering with a pass is a very good strategy, especially in slippery conditions.