Crossed-warp Braids from the Andes
I came across instructions for making these narrow decorative braids in a book by Adele Cahlander called Bolivian Tubular Edging & Andean Crossed-Warp Techniques (ISBN 0-932394-29-2). In these braids the warps are manipulated to change their positions and the weft is passed from right to left. Then the warps are returned to their original positions and the weft is passed from left to right ready for the next warp manipulation.
The simplest braid has 8 warp threads and is set up with two colours which are manipulated in two ways: either the A method or the B method, usually to give a zig-zag pattern (braids 1-4 from the left below) but other patterns are also possible (braid 5 from the left below). Wider braids with 16 warp threads can be worked with two or three colours and usually have a diamond pattern (braids 6-9 from the left). With three colours small shifts in colour are possible as in braid 8, where the green and and orange threads change places.
The braids below were worked with yarns of various thicknesses and fibres (wool, cotton or acrylic), most of them intended for knitting. Smooth yarns work best and anything at all hairy or fluffy should definitely be avoided.