You DO NOT need a PayPal account to leave a tip. You can tip with your credit card! From the PayPal page, enter the amount to give, update total, then click on "Continue" where it says "Don't have a PayPal account? Use your credit card or bank account (where available) Continue"

Confession: Tips are used to support my knitting habit, which will result in more classes and patterns for you! Ok, did that sound convincing?