Easiest way for me is to just do a fully concealed hand (so don't take other tiles from other players), and just aim for 4 sets of 3 consecutive tiles and two of the same tile for the double. So usually the best way to achieve this is to discard any wind or special tile right away unless you have 2-3 of the same tile for a set, and then just focus on trying to get 4 sets of 3 consecutive tiles (or 3 of the same tile, that is accepted as well).
Also, its probably best to ditch tiles 1 or 9 unless you only need one last tile to make a set, since they are harder to complete as you'll need one specific tile. For example:
If you have tiles 1 and 2 you will need to get a 3 to complete your set, and only a 3. It can be tricky as you are relying on just one tile to come into your possession so the odds are lower for you to win. If you have tiles 2 and 3, then you need either a 1 or a 4 for the set, so you have more flexibility and better odds on getting the tile you need. Set the "Red Dora" option (I think that's what its called) in the Mah Jong menu and you have a chance at getting special red tiles which are still numbered just like normal, but should you win a match with at least one of these tiles in your possession you'll get a points bonus.
