Making big hands and playing premium starting cards aren't the only way of winning in poker. If they were then the game wouldn't be half as much fun and wouldn't be surrounded by as much mystique and legend as it is.
Although bluffing is an important part of poker many players overestimate its strength, making the mistake of bluffing too often and at the wrong time. The key ingredient to successful bluffing is information. You need to know the people you're up against, the situation you're in and have an awareness of your own table image.
These three pieces of information can be summed up quickly like this; if you're up against a poor player who calls with anything then you're wasting your time bluffing. If they have hit anything then you're going to get called. Learn it now and remember it forever - you CANNOT bluff a calling station!
Dependent upon the situation you're in you should always consider whether a bluff actually has any chance of succeeding. If it's a single-table tournament and you're trying to bluff a player with just a few chips left then you're probably not going to be successful. In tournament play desperate players will often call with their last few chips and you should always bear that in mind. By all means, put them on the spot for all of their chips if you can easily afford it, but if you don't have all that many chips yourself then bluffing in those sort of situations can be very dangerous.
Your own table image is something that is often not considered by players when they're playing at a table. If you are someone who has been playing very tight for many hands then your bluff has a much better chance of succeeding. Opposing players will suspect that you've finally got a hand and will show more respect to your bet.
However, if you've been betting and raising a lot, and especially if you've been caught trying other bluffs, then you're much more likely to get a call or a re-raise when you attempt your latest bluff. Just as you notice the pattern of behaviour of other players at the table, they are as likely to notice yours.
Information also comes in the form of the cards you can see on the table. If there is a possible flush or three or four cards to a straight then you've got to decide whether the players you're up against have made that straight or flush or whether they'll believe that you have those hands yourself. Their patterns of betting will hopefully have given you the clues you need to make your big decision.
What you really need to do is to pick your moments well, before you bluff, and after you feel you've got at least some idea of what your opponents are likely to do. Observe other players and their pattern of behaviour and notice if they're unlikely to bet unless they've got a good hand. When timid players check your chances of successfully bluffing them out of the pot are so much greater.
If you're close to reaching the pay-out structure of a single or multi-table tournament then it's usually the case that players tighten up in an effort to make it into the money, and this can be a great time to bluff and steal pots. Again though, you should always be aware of the players you've got at your table and how they're likely to respond if you try to bully them.
In poker you have the stone-cold bluff and the semi-bluff. The stone cold bluff is where you try to win the pot with no hand at all of your own. This is the most dangerous move of all and needs to be executed perfectly, especially in No Limit games, or Pot Limit games where the pot has grown substantially. If you get this move wrong then you're probably going to lose a lot of chips and possibly even look a little bit stupid.
The semi-bluff is usually the better way to go. This can be defined as making an attempt to win the pot when you don't have a made hand, but do possess one which could improve with the addition of another card, even if it is a long shot to hit for you.
An example of a semi-bluff can be shown here. Say you have A-10 and the flop comes down J-9-8. You have nothing better than ace high at that moment but if you do try a bluff and are called then you still have the chance to hit a queen or 7 for your straight and also an ace to give you the top pair. Even if you're called by a better hand you still have a chance to make a stronger hand yourself.
The advantage of the semi-bluff over the stone-cold bluff is that you have two ways to win with it. The stone cold bluff can only win if your opponents fold. However, the semi-bluff can win if they either fold or you hit the cards you need to make your hand!
Bluffing in poker is an art-form but it is generally harder to bluff online than it is in a bricks and mortar casino. You have less tells to go with as it is usually much harder to read your opponents through a PC screen.
However, if you practice enough and always remember the golden rules of information and timing then bluffing can be a very profitable exercise indeed.