The invisible join is a great finishing technique to use when working in the round. Normally when finishing off a crochet project you would finish off with a slip stitch. This slip stitch, no matter how tight you pull it closed, always leaves a bump when you ended your project. The invisible join method prevents that little bump from happening. With the invisible join, you are left with a seamless and more professional finish.
To see a detailed picture tutorial click here. Or, if you prefer video tutorials watch the video below.