Get it up to 160+ in my opinion. At low levels I think every CHA point counts. Pyrion is right, use weakish mobs and root the target so that you don't have 2 mobs coming at you on a charm break.
12-20(?) are the hardest levels, it does get easier - but build up that CHA stat!
[You must be logged in to view images. Log in or Register.]
Golden Cat Eye Bracelets (costs JCs 11pp or so to make) +7 cha each...they'll help if you haven't got a pair already.
Crude Stein (usually cheap to buy also but check the Oggok vendors and the surrounding area in Feerott)