I have noticed a few common signs that point out a fish to me. if i see one of these signs i will put 'S' in player notes, if i see another i will put 'H' until it spells 'SHIT' then i basically know what kind of player im dealing with.
here are a few signs i have noticed.
1. if the minraise preflop, i.e. the raise to (0.5) at 25NL - A good player would not do this as its pointless.
2.if the reminraise before or after the flop. such as post flop somebody bets 0.25, they then remiraise to 0.5, even more so if there opponant then reminraises to 0.75 etc.
3.if the have the 'Bet Pot' option checked before or after flop, players can miss a lot of opportunities using this.

I have never seen a good player do any of these things.

other, more obvious things are pushing allin for $20 into a pot of $2, not just once but often (more than once every 5 hands) - its a recipe for losing money.

calling bet bets on the river with middle/bottom pair, or an AI on a draw etc.

has anyone else noticed any more 'tells' for bad players?