Basic rule of jetting a 2 stroke is first off, warm the bike up before you attempt jetting the idle. Also check your float level too, cause you cant get jetting right if the float is off. Once youve done those 2, your pilot selection should be the jet that makes the idle kick up the highest but not be more than a couple turns out on the airscrew. So example. If you have a pilot in there, and you have to turn the airscrew out 4 turns to get it to idle the highest, youre too lean. Likewise, if you can turn the airscrew less than a turn (some say 1.5-2 turns) to get it to idle, youre too rich. You should have the highest idle 1.5-2 turns out. Anything after that shouldnt affect the idle, and anything before that should bog it down. Once you get your pilot set then check your main. Main jetting is a bit easier cause you can go high on the main, if it bogs, pull mains back till it doesnt bog. Plug chop it, and if its that mocha brown color, youre good. If it isnt, adjust till it is.
The jet needle is the trickiest one to jet, cause you could have good idle and good top end but crappy transition. The jet needle controls the midrange of the bike, and is probably the most important aspect of jetting. There are clips on the needle, lowering the clip down toward the tip raises the needle so it richens the mixture on mid. Likewise raising it lowers it down and leans it out.
Jetting is easy on paper, but in real life, its pretty tough till you get experience of what a lean poppy/boggy engine sounds like, and a rich sputtery engine sounds like. Also, sometimes the butt dyno lies because to a point leaner makes more power, so not always what feels good is what the bike wants.
Hope this helps, Ive learned through some hard times how to jet, and trust me, it can be a biotch, but it is a nifty skill to have, and it WILL save your ass knowing how to do it right.