Just thought I would expand on this:
Practicing keeping the kite at 12 o'clock (directly above you) is the biggest advantage of a trainer. On a small trainer, it is completely safe for you, and the "fast turning" property of a small trainer teaches you to steady a kite in high winds - even when the wind is light.
You do need be aware that 12 o'clock is not a place you want the kite when you are on land, and especially in gusty conditions on land. But you do use this position in many situations such as:
1. putting on board
2. transitions (flying through 12 o'clock)
3. Flying extra high when passing upwind of another kiter who does not get the concept of "downwind kiter puts kite low"
With a tiny trainer, you should be able to almost tie your shoe with one hand while steering with the other, before you consider yourself ready to put on a twin-tip in the water. Those that have this skill before moving onto full sized kites skip lots of crashes, and just plain time flopping around in the water, on their first lessons.