Probably the most important factor in getting it to flower, is not to repot it,
 but let it get quite cramped in its pot.
Also make sure it has plenty of light (though not _too_ much direct sunlight) and enough water - 
I generally give mine a good dowsing as soon as its soil has completely dried out - and then even
 leave it to stand in a small amount of water until that evaporates.
In my experience they like quite a "peaty" soil.
Also, it's just possible that occasional music has a beneficial effect (ours is in the living room
 and gets quite a lot of passing attention/TV sounds etc. to stop it getting lonely!!)