I have a friend who knits and her general charge is (cost of yarn)+15%=(cost of item) for simple things and up to 25% for more difficult things. And she always takes into account things like if she likes the person she's knitting for, if it is something that is going in a shop and if she enjoyed the process.
"The world now has the means to end extreme poverty, we pray we will have the will"
knitncook there, too!
OTN: Laughing Carrots; Jaywaler
FO: Potamus socks; Palindrome