Welcome! I have lots of fun with this. Obviously they're never going to be the oreo tell from Rounders, but lots of helpful info from low stakes mooks. To start, after you fold just watch the people driving the action. How they sit, hold their cards, spend time between action, and what they have if it goes to showdown. If they show up after having limped UTG with Q6o and flopped a boat, compliment their play and immediately mark them as a fish lol.
Before you bet preflop look left, you'll often see people holding their cards ready to fold, or staring straight into your soul ready to 3bet. Saving yourself a bet here and there really pads your win rate at the low stakes, especially trying to beat the 1/3 rake. Big difference opening in middle position when you know for sure 2 or 3 people have already mentally folded.
The obvious weakness means strength is played out but works, listen for the stupid sigh before they shove or the need to explain why they're doing something."cant let you push me around anymore! Or "i dont think you have anything, I raise". Make sure to compliment the person to your left, told a mook I liked his hat, we talked for 20 about the UGA Dawgs and he literally told me when he had aces. Saved me a 3bet!
Yes, people can reverse these tells but poker is a game of unknowns and low stakes poker is easy. Fold to the river bets and push value when you've got it, these are just edge cases.