To make a base to hold the warp for the tapestry sections I used a needle lace method: the actual-size drawing on paper of the pocket opening was reinforced with a backing of fabric and a covering of clear plastic. On the drawing I marked each of the seven warps. The base extended far enough under the fabric edge that it could be tacked in place with holding stitches.
I held the warps temporarily in place with bobby pins/hair grips.
Then I secured all the warp threads in position with holding stitches.
I wove over pairs of warps to make a weft-faced padded band. The fabric edge and the first strand became the first "pair" of warps.