I highly suggest to change your play-style often or in every deal. The game of poker both involves luck and skill. Luck, in terms of the cards on the pool; and skill, as your observation and prediction skills will be put to the test.
What most people fail to acknowledge is that, whenever people try to predict or observe the movements of a specific person during the game, LUCK also plays a role in determining if your prediction is indeed right.
Like what I have previously mentioned, try to change your play-style every now and then. If a person tries to call your bluff, then take it as a sign that they are reading you.