After your opponent has passed your guard and tries to settle into a solid side control you should try to get your guard back as soon as possible.
Variation 1 – Shrimp
Frame with your arms, then shrimp and re-guard.
Variation 2 – Turtle
Frame with your arms, then turn away to turtle and granby roll to guard.
Variation 3 – Invert
Frame with your arms, then invert to guard.