Because each installation is fairly unique (your closets aren't going to be exactly the same size as mine) I won't be giving a detailed set of plans. I'm assuming (dangerous, I know) that you have some modicum of woodworking skill before tackling a project like this. Although it IS a fairly simple project, it does require some precision.
You do not need to have a shop full of tools to build something like this, however, you will need to make up for whatever tools you lack (like a jointer and planer) with outstanding hand-tool skills, or, a trip to a cabinet shop where they can dimension the lumber for you.
For those who are familiar with traditional Shoji design, construction, and installation, you will see that I used a lot of ... uh... "alternate methods" which work - but aren't exactly "traditional" - I hope the Shoji Gods forgive me :) I recommend Jay Van Arsdale's book "Shoji: How to Design, Build, and Install Japanese Screens" to anyone interested in traditional construction and installation.
Finally, the project cost about $400 total - that's for the wood, shoji paper, finishing materials, and quality hardware - not exactly cheap, but also nowhere near what these would cost if you had them made.