I can do commisions, I am afraid that I can do just the Vector drawings, some image editing and simple digital drawings.
It would depend on what you want.
One simple character (for example one pony, those are really simple) and no background I would do for free.
The same goes for when I suddenly got an inspiration to do something without anyone asking me to do it. Those, if not overly complicated will also be free.
If you are author of story, and want a cover, you can try sending me some of it. If I like it enough, I might make it for free.
For things more complicated I would like to charge a bit. (I am having some problems recently, and I need some more motivation to do anything. ) but I would not charge anything more than 5$, it's just that digital vector art is quite simple, and only thing of value here is time. Things like this markoatonc.deviantart.com/art/… can take a bit more. But I actually did that one for free, because it was an experiment, I never before did any pokemon art, so that was an exception.
(well unless you want massive picture with tons of unique and detailed characters, then I might make an exception and charge more.) I can also promise haste with doing it.