The above illustration of frolicking sukumizu clad schoolgirls appeared in Dengeki Moe-Oh some months ago as part of a how-to article on drawing sukumizu, surely an essential skill for aspiring illustrators.
The creator has recently published a sukumizu illustration guide on his site, focused on the finicky business of colouring and reproducing wetness, so should you be of an artistic bent, or simply curious, you might want to check it out. Stretching to three pages, it is quite detailed.
If you are interested in this, you may also be interested to view the video of master CG artist Ino creating one of his works.
A few of the images in question give you a good idea about it:
Forget the sukumizu, is that how to color that type of hair? Dangit, I’m dumb for not figuring out the obvious. x[
I wish somebody would translate this, so I could get some tips on how he’s actually doing this in SAI, but I doubt thats gonna happen anytime soon.