A mistake I made a lot early on in my poker career was caring too much about figuring out what the other person has and neglecting to be deceptive about what cards I was holding. Withholding your information from your opponent is just as vital as trying to extract it from them! Many opponents weak-lead (if out of position) or re-raise a hand like KQ on a K-8-7 board to “protect” it or even worse “to get information”.
This is bad because not only does it often make you miss out on chips by stopping your opponent from c-betting, but it also telegraphs your hand to them by letting them know that you’ve hit the flop. Your goal is to make your opponent’s life difficult for them and always keep them guessing.