Roo has suggested using mineral oil on a Q-tip to help remove skin that doesn't shed by itself after a couple of days.
Don't pull the skin as stated before but work it off by gently rubbing.
This is only for stubborn skin that stays on for more then a day or two.
As for misting....some people have experienced that extra misting causes the skin to stick more and hinders a good shed. They recommend letting the animal dry out a bit.
I, however, have found a lot of misting during a shed to be quite beneficial and really speed the process.
We're in a really dry climate here, so that may be the difference.
A little trial and error will soon tell you what is best for your cham....where-ever you live, but ideally everything will just work out perfectly on it's own.
By the way, in the first 6 months or so a shed every 3 or 4 weeks is normal.
-Brad