So here is an example. You have pocket kings. Your opponent, who is under the gun, raises to 500 with blinds of 50/100. You call, hoping for no ace.
The flop shows J 10 A. Your opponent bets all in to you. You can break this hand down from here.

Ask yourself these key questions before making your decision.
First, is my opponent a know bluffer?
Second, Did my opponent raise preflop and how much? In my example, the opponent raised 5x the BB. This leads you to imagine he has an ace, possibly two pair, Aces and Jacks.
Third, Are my pot odds allowing me to call? In the case with the all in player, imagine his stack is for another 300 chips. This can change your entire outlook on this.
So, your opponent didnt go all in for another 300 preflop, which means he may have high suited connectors like KQ, giving him a straight. There is now 1250 in the pot, as well as his iadditional all in of 300 which makes the pot 1550 to you. So you're getting about 5:1 pot odds. This can really change how you decide on whether ot fold or not.
Now in this situation, with a big stack, i will call only because i have comitted to the pot and if my opponent should have an ace, i still have outs.

But, imagine the player's all in is for 1500. This is an easy fold, one because youre pot odds are almost 1:1, which cant get much worse, and two because your opponent raised a substantial amount preflop, probably giving him an ace. Also, you have to remember your opponent raised UTG, which is a gutsy move without a hand. It isnt often a player will bluff UTG.

So, to simplify the topic, remember to note your player's preflop moves, post flop moves, and any other street that is needed to come to a decision.
I havent really explained the meaning of betting patterns, so here it is.
Betting patterns is the pattern your opponent is betting. Redundant i know, but it goes without saying.
If your opponent bets on the flop, and checks on the turn, he was probably either slow playing you or was waiting for a draw and did not hit it.
If your opponent bets more on the flop than they did on the turn, it is usually either one, because of an overcard or two, because of a protection bet to cover for the bluff.

This is not so much a tactic as it is using your head. I can guarantee using this skill will really helpy oyu in the long run.