Braap,
Jetting is really an individual thing, by that I mean it depends on your climate, track conditions, engine mods, pipe/silencer set up.
I had a 04 yz250 for the 04/05 season and the only jetting changes where to go up 1 size on the main and drop the needle a clip or 2.
If your bike is standard, start by raising the needle clip (dropping the needle) a clip at a a time and perhaps one down on the main.