One of the most difficult situations you will have to handle with strategy is discarding early on in the hand. Since you know very little information except for the tiles in your own hand, it can be difficult to come up with a strategy for discarding early. Beginning players almost always start discarding from the high tiles and working their way down. Unfortunately for the better players, they often keep up with this habit, much to the detriment of their game.
The idea is that your point count should be reduced as much as possible, but playing against these opponents also gives you an advantage as long as you are not one of them. While they are discarding all the high tiles you can hold your high tiles and let them fill up your melds. In this way, they get rid of one high tile while you meld at least two of yours. Conversely, if you discard low tiles, your opponent can only pick them up to fill low-count melds. This may encourage him to discard higher tiles to you. If he is a good player then he will realize what you are doing and will start discarding in the same range as you, but it is often worth the risk at first.
Most discarding tends to occur in groups around the same numbers and colors because these are the safer tiles because some of them may be known to be out or dead. This fact can be used to your advantage by discarding “bait” tiles. This is when you are basically discarding a tile that will bring you back the tile that you need. This is a tactic that can only be used so often before the other players realize that you like to do it. Therefore, it should be done with some candor and discretion. It is always smart to consider which tiles can be used as bait tiles when you have a choice of several discards, by taking into account all the other factors. The bait tile can be very attractive if all other factors point in that direction.
By watching the discard patterns of your opponents you will quickly notice their pattern. If one of them make s a discard out of their normal pattern, you can be reasonably certain that they are fishing for specific tiles. Fishing is most often used when you are playing a single opponent versus two or three opponents mainly because the response is more immediate which gives you the time to really focus on what you or they are doing. If you are playing with good players who carefully watch all of the discards, this tactic can still be very useful. By constantly fishing you can even disorient your opponent until he is basically afraid to throw any discard close to the ones you throw. Eventually this forces him to hold a lot of useless tiles and it lets you throw odd tiles from your rack with great defensive effect.