When you are playing online poker, you should always try to think more than one step ahead. The best chess masters have a plan for their entire game – just as the best online poker players have a plan for the hand they are playing. This means that to be as successful as you can be playing online poker games such as no limit Texas Holdem, Omaha Hi and Omaha 8, you need to plan your moves before you play them.
As a simple example, instead of just deciding to check because you feel it is a good decision, you also should analyse what you do once your opponent replies. For instance if he checks behind, what do you do on the turn? If he bets, do you fold? Call? Re-raise?

When to Check-Call
Check-calling is useful in a number of situations. If you are slowplaying against a super aggressive, maniacal opponent and you hit a massive hand on the flop, a good plan is to check then call his bet. Repeat this on the turn, then when he bets the river, put in a big reraise. If you were to check-raise instead of check-calling on the flop, your opponent would get very suspicious, maybe managing to get away from his hand. The best thing to do to players who are too aggressive is let them hang themselves when you have a huge hand.

Another situation that gives a valid reason to check-call is when you are drawing to a potentially very good hand. For instance in a game of pot limit Omaha Hi, you might have a wrap straight draw on the flop, needing just one more card to complete your hand. Here you might check-call a pot sized bet, since you have the implied odds to allow you to draw to your goal.

When Not to Check-Call
As a continuation of the example above, suppose that your straight draw doesn’t complete on the turn, and your opponent fires out another pot sized bet. Now you probably are not getting the correct implied odds to call his bet, so you should fold and save your money. Blindly check-calling without taking into account the odds of completing your draw is a quick, sure-fire way to lose money; lots of beginning players do this. Take full advantage by betting your strong made hands to the maximum extent possible.

Check-calling is a nice middle ground between check-folding and check-raising. Also you can disguise the strength of your hand by check-calling, as demonstrated by the example of playing against the aggressive player. Many aggressive players do not have the discipline to fold their hand on the river like that, so take full advantage of the situation.