Hi Dafish,
I would suggest progressively working on edging your foil in low winds which is a skill you will develop over time and will help control your speed. In the same way you ride a twin tip or a surfboard, you should be able to edge enough to slow yourself down to a stop. Of course this is much more difficult/technical do to on a foil.
When I go too fast or a gust of wind hit, I simply sheet out (trim the kite correctly as well) and edge the foil slightly more upwind. Choosing the correct kite size is critical here also...
Hope this helps,
Christian