1. Always attack, unless you should be defending.
2. Always defend, unless you should be attacking.
3. If you are an expert like me, you can even try attacking and defending at the same time.
4. Only deal tiles that other players cannot use, or you will be helping them form their hands.
5. When other players are in tenpai, it is important that you do not deal into their hands.
6. Make other players deal into your hand by waiting on unexpected tiles.
7. Always score as many points as possible.
8. Win as many hands as you can.
9. It is silly to call tiles when you can always draw it yourself anyway.
10. Do not discard tiles nobody has discarded, or that anybody has discarded early, mid, or late game. If possible you can consider not discarding at all. But it’s a double-edged sword. I can’t recommend this to amateurs.
11. Always remember what your tiles look like, in case of sudden blindness.
If you are an expert player you are welcome to leave any of your own tips.