im glad your checking your plugs. it really is the only way to get these things running right.
personally id also make sure the exhaust is in tip top condition. the ehaust on 2 strokes makes a big impact..
on my rxs if i had some how managed not to attach the exhaust properly the thing would rev like no ones buisiness. and i can guarantee it would have exploded if i tried to ride it any where like that. but it sure did sound like it meant buisiness.
personally i like to set everything up to a basic level. "pin in middle setting" start it adjust the mixture via carb screws till it sounds good running at idle "i like to do it by ear, if the idle sounds good to me then i will let it just idle for a while. make sure there arent any differences in the idle noise "speeding up slowing down" if it seems like a good idle setting.
makes sure the plug is clean. then go rag it arround for a while. then bring it back home and check the plug(s).
Hopefully it will be the correct colour if not then its time to adjust.
I do tend to set up a bit to lean when i do it by ear if im honest, rev counters help with that. not all 2 strokes have them though. but if you do have them use them. but running a bit lean you would tend to hear slight differences in the noise whilst its in idle.
if i go by the above picture. id say that i usually set up aiming for picture number 18. and then id be happy to not mess with it any more.