Measure your extension-hair for the perimeter braid.
The very first extension that you will measure and apply is the bit that goes around the perimeter. Take your extensions from the bundle, and start a single weft so that the hair is exposed. Starting at the beginning of your perimeter braid, maintain the extension set up, and wrap it round your head. Hold it to the perimeter braid the entire time to be certain it’s the right length. When you get to the close of the perimeter braid on the opposing side, measure a little extra hair, and then trim it to fit.