Pick an opponent and go through all hands that went to showdown. Figure out what he doesn't cbet. Work out how he plays his strong draws, his nut hands and his bluffs. Go through all c bets and see if the sizing changes then see if the sizing changes based on the board texture or the strength of his hand. What turns does he bet when he bluffs? Does he ever triple barrel bluff? Do his lines "make sense" when he bluffs? Does he bluff ALL missed draws on the river? How thin will he bet for value? Often you have to use the information from the hands you have seen to extrapolate so for instance he calls on a two tone flop and turn the flush comes on the river you check the river and he checks behind with the king high flush...You can then probably assume that whenever a flush comes in and he has position and bets the river his range is polarized. Or a similar situation except he check calls OOP and the flush comes in on the river he checks to you again and you decide to check back with top and bottom pair. He shows the nut flush, you can then assume unless he misread his hand that he was going for a check-raise so perhaps if in a similar situation when he leads out on the river you can take those hands out of his range. 

Another thing to do is to record your sessions using a program such as camtasia, often in heads up people are paying more attention and therefore their timing tells are more "honest". Go through and watch when he tanks. Does he ever fake-tank with the nuts? Does he do it every time? Usually instant actions are polarized, i.e. either the nuts or a bluff they decided they were going to do long ago. Does he ever snap raise as a bluff?

I could go on forever but I will leave it there.

Also, if you do find something like someone always tank raising with the nuts, do not start instant snap folding every time or showing the second nuts or writing stuff in the chat. Just get it quietly.

Gotta play loose aggressive for that to happen. Just play a lot, watch some vids, don't be afraid to go for it and instincts about how your opponents perceive you and how light they will call you will develop. I mean a tight player can't really get in your head cause he usually has it, it's a paradox. At least that's how it worked for me. AND QUIT IF YOU TILT, can't be the puppeteer when you tilt.

Thx for answer

Darley_arabian very helpful post, if you can then write more :)