I'd like to do a couple repaints with a black base, but I have no experience doing it at this scale or with these kinds of models.

Coming from 28mm miniature painting background, I'm accustomed to most "black" paintjob actually being done in dark grey with black shading, or in black with grey/white edge highlights.

The standard X-Wing repaint method of using washes to darken crevices and panel lines won't really work with a pure black base, so I'm curious how people go about achieving the black look.

Any tips and/or pictures of your black ships?

https://m.youtube.com/watch?v=ZAEo6C6vp9U

A very nice black Lambda-class shuttle. It is painted black and then highlighted.

Hi.

I am not sure if it is over the top for painting small x-wing ships but I can recommend the tutorial by the Massive Voodoo crew on painting black:
http://massivevoodoo.blogspot.de/2014/05/tutorial-painting-colour-black.html

good luck.

Use a brush!