Hobbies And Interests
Connections
Look over the tiles you've drawn and seen which ones are "connected"--that is, which tiles can make a meld with just one more tile. These tiles will naturally help you decide which tiles to look for. This includes two identical tiles, which can be used for the pair or be built into a Pung or Kong with one or two more tiles. Two tiles of the same suit in sequential order have the potential to make a Chow; however, some are not as strong as others. If you have a one and two in succession or an eight and nine, there is only one type of tile you can get to make that Chow (a three or seven, respectively). Therefore, you may not want to hold onto that pair. The same applies to tiles of the same suit that are separated by one number, like a four and a six. All other connections for possible Chows are considered strong.
Chows vs. Pungs
Chows can be easier to build than Pungs provided you have a strong connection. This is because you have twice the potential tiles to draw from; there are only four tiles you can draw to complete a Pung, but eight possible tiles for a Chow (you can draw the number before your current connection or the one after it). If you have a pair of matching tiles and then draw a tile of the same suit with a connecting number, you can discard the other identical tile and go for the Chow rather than the Pung.
Kong Building
If you have a concealed three-tile Pung, use caution when turning it into a four-tile Kong. If you draw from the discard pile to form a Kong, you have to expose that Kong by turning it up. You may have a meld, but you also have four identical tiles that you won't be able to use to form Pungs should you get more matching tiles.
Patience
Don't rush to build many melds as quickly as you can. It's not a good idea to grab a tile that another player has immediately discarded, as it tips off the others as to what you have. This can affect how they discard tiles for the rest of the game, making it harder for you to get tiles you need. Also, don't look to build all the pairs you have into Pungs. Try to keep one pair as it is throughout the game because it's harder to build a pair at the end with just one tile.