I have tried another way of finishing off, usually used for small tapestries. It involves lots of hitching but allows you to hide the white warp threads reasonably successfully. I did this with the historical piece and my miniatures.
We had to do miniature tapestry weaving for one of our assignments and I decided to make three small pieces to go into a doll's house. It is based on some Art Deco designs and furniture I have seen lately.
There is a lot of hitching on and off with this technique but I like it because you don't have such an obvious, white, edge where you usually plait the warp threads. You use double half hitches and soumak, with a full pass of weaving with the thread you are using (I used stranded cotton for this piece) and also one of the seine twine used in the warping up.
When you are finished, you pull out the seine twine and fold the work over in that space, sewing through the full pass space, through to the front.
As I said, I used stranded cotton more commonly used for embroidery. It was comfortable to use but does slip up and down the warp rather easily.