>>28440231. Have a full body or at least the parts that will be visible.
2. Have clothes on top of it and lower in the material list than everything which should be visible through them. Note: if a part of such clothes could be visible through another part—like with a loincloth or the skirt in the linked video (the author of which didn't bother with the following)—you will have to split them into separate materials. The best idea in such cases, though, is to have a non-2-sided material without an existing underlayer, copy it in full, and reverse the faces (PMXView -> Edit -> Face -> Reverse) so that you will be able to see the other side from any angle. If your clothing has an existing underlayer, all you need to do is to split it, which can be done by selecting some faces on the underlayer with FRNT (front-facing vertices only) enabled and hitting Ctrl+X.
3. Create a material morph that reduces the alpha/opacity of desired clothing materials (including the alpha & size of their outlines) (alternatively, set all to 0) and register it on the display pane.
4. Within the project, make sure the rendering order of your model follows everything that could be seen through it.
5. Keep in mind that if your clothes have attached physics, they will still affect and be affected by anything that collides.
