Live cards beat pretty cards

Your (J♠T♦)J♥ looks pretty until three jacks and two tens are already up for others. Dead cards kill hidden pairs and draws.

Before you put money in, scan the board: are your pair cards live? Are your straight/flush outs live? If half your outs are dead, your 'strong' hand is a bluff-catcher waiting to happen.

Habit: before acting on third, name your two most important outs out loud (quietly). If you see them up, downgrade.