Instructions
Cycles
Get the Ngan cycle. The Ngan cycle is when you have two identical tiles, such as two "4 thousands" or two "red dragons." Ngan is needed for every hand, so completing this cycle should be your first priority. Get Ngan by discarding an unnecessary tile and picking up a tile that is identical to any tile you have.
Complete the Pung cycle. The Pung cycle is when you have three identical tiles of any suits, dragons or winds. For example, you can win with three "3 red dragons" or three "4 bamboos." Complete your Pung cycle if you already have two identical tiles in your hand and you see the other one in the thrown away pile. Discard a useless tile to pick up the one you need.
Complete the Sheung cycle. The Sheung cycle is when you have a run of three tiles from the same suit, such as "7, 8 and 9 bamboos" or "1, 2 and 3 circles." Complete your Sheung cycle if you already have two suits in a row and a third is in the thrown away pile. Discard a useless tile from your hand to pick up the one that completes your cycle.
Complete the Kong cycle. The Kong cycle is when you have four identical tiles of any suits, dragons or winds, such as four "7 circles" or four "3 bamboos." Complete your Kong cycle if you already have three identical tiles in your hand and the fourth is in the thrown away pile. Discard any unnecessary tiles to pick up the one that completes your cycle.
Strategy
Go for Pung or Kong first. A player can win with four Sheung, but Kong and Pung have priority over Sheung. If you are close to getting Kong and Sheung, complete the Kong cycle first then complete the Sheung cycle.
Leave your tiles alone. Grouping your tiles can let your opponents know how close you are to winning the game. Putting your tiles in a random order can make your opponent underestimate your hand and give you a winning advantage.
Keep track of the tiles you have thrown away and the other players pick up. If your opponent picked up a "4 and 5 bamboo" then you should not put down a "3 bamboo" or "6 bamboo."
Pick up tiles that you need and have a plan for how to use them. You can lose valuable opportunities if you have useless tiles in your hand and a necessary tile is in the thrown away pile.