Have you noticed how the edge beads on loom work is still open on the side?  If you prefer to have a row of edge beads facing the other way, check out this tutorial!  It is by Erin Simonetti of Beads, Beading, Beaded.

It is a very clever tip as the edge beads (which do not have to be a contrasting color) are first strung on the outer warp threads.

I think it is also a good guide as to the finished length as you would have determined how many outside beads you need to string on.

H/T to Marilyn Gardiner on Facebook.