Just an overview, front and back views, maybe a bit low-res but I think you can make out the lacing.

I did the transparency maps. and the texture for the catsuit, in an oldish version of Paintshop Pro, starting with a large export of the texture template from UVmapper. Make sure the mesh is not in a colour you plan to use, so it can be easily distinguished and selectively erased. It's also worth adding index marks for the front and back centreline of the body.

You might also want to put some marker dots outside the mesh as a guide to key points. Colour is useful, even if you put all this on extra layers.

I then did the transparency map. Start with the boundaries. I used the line tool. several pixels wide, and removed less rather then more, flood-filling with black. And there was a lot of flicking between PSP and Poser, to judge just where the boundaries were on a 3D figure.

The lacing was added later, by drawing white lines.

In retrospect, it may have been better to make two layers containing the mesh template. The second would be the working layer. Convert to coloured mesh, flood-fill outside with black, and then colour-replace the mesh to white. But I'm not up to speed on using layers, and saving in a Poser-usable format could be awkward.

It is definitely better to work on a very large original, and reduce the final size to suit, but keep in mind how wide the lacing would be on the final transparency or texture. It's a bit of a waste to draw a 4-pixel line on a 4096x4096 master copy if your working copy is going to be 512x512.

Remember to check out fonts such as Wingdings for useful symbols. If your paint program doesn't let you rotate fonts, put it in a scratch image, rotate that, and cut-and-paste.