Yes, I do this if I can, mainly for backgrounds if possible, because they take ages to draw and aren't paid attention to lol. Sometimes for characters too, and no I don't consider it cheating either.
I work for around 6-7 hours a day on comics, between dc online and manuscripts, that's a lot of drawing, and some very angry hands I'll have. So if I can save a few seconds of discomfort from drawing something near identical, then I'm up for that! Plus you see examples of it everywhere, in most comics you'll see, so it's pretty accepted. As long as it's not really over-used and obvious then most people don't mind.
Plus I think, well, I drew that background or whatever in the first place, so it's not cheating to use my own self-made content again in a couple other places. XD