Here is a little video on making a “Wave” Braid.
Beginning with eight cords, first split seven cords with the left-most cord, then split the remaining six with the now left-most cord, then five…. When all the cords are split, pull each cord very tightly to bend the braid into the “wave”. Turn the piece over and repeat the process.
It is important that all the splits are “quarter twist”.
The basic splits and the Wave pattern can be found in Julie Hedges' book Ply-Split Braiding An Introduction.
www.louisefrench.com