I also play micros at UB and run into this often enough...

I think you are right about taking the notes when it happens. That's step 1. But if you are against someone who you have no notes on, how do you know? Typically what you'll see is that they will slow play it from start to finish. There's no good way to read them. I guess, say, you are in a pot with 4 other preflop limpers. You've got QJs in LP. Flop comes up Q rag rag rainbow. Checks around to you, you bet it strong, get everyone to fold except 1 other guy, who just calls. Flop is another rag, same thing. River is another rag, and you still lead out, then they raise you. This sucks. Pot sized bets can get big when 5 people limp.

Counter strategy is to not get as aggressive with betting out your top pair, but something tells me that isn't best in the long run.