If you blank mid-bit, what’s the best thing to memorise as a recovery point?

I’m trying to make rehearsal less about knowing every word and more about being able to find my way back if my brain disappears for five seconds. Would you deliberately memorise the first line of each bit, the punchlines, a few anchor words, or the transitions between sections? I’m interested in what gives you the smallest useful map of the set without turning the whole thing into a script.