sometimes bluffing, showing cards can explain to the players if we really lie or not showing the
The worst thing to do is to show the folding hand that shouldnt be folded. Never show your weakness. Like you have ace suited on big blind and you fold to a min bet. Never show that. Unless you want to have a target on your back.
Sometimes having a target on your back is advantageous, IF you only do it once, and at the right time, against the right opponent. I think the worst thing you can be is totally predictable. If you can find ways of making other players think you have a screw loose without losing too much of your stack you can really cash in.