one tell I spot from a good player once is everytime he limped preflop instead of raising, he folded to my prelfop raise. Every single time.

Other tell, guy called a preflop bet from somebody. Then checked call flop bet with 2 spades showing. On the turn, 3rd spade, he started to breathe heavely, and checked. The other player checked behind. On the river, he bet out and the rest is obvious.