The only leather skirt I have ever owned, was a black, hipster, A-line wrap-around mini-skirt which I wore with black opaque tights and a black, fitted sweater, about 7 or 8 years ago.
It wasn't too tight and I think it looked more '60s mod, than trashy.
I think my basic rules (for me!) are:
1. Only wear shiny materials (including leather), on your bottom half, if it (your bottom half!) is fairly slim. As shiny fabrics are not flattering!
2. Unless on a motorbike, never wear leather with leather; always with matt fabrics, like cotton, or wool.
3. Regardless of fashion, a short, tight, leather skirt is only ever wearable if you are fairly slim and you wear it in Autumn/Winter, toned down, with a loose fitting or baggy jumper, opaque tights and flat heeled boots.
Having said that; I don't feel that leather (particularly unembellished, black leather) is very 'in' for clothes at the moment and the last leather item of clothing I owned (my fitted leather jacket), I haven't worn in about five years.