I personally don't think "copying" is cheating per say. I using references definitely makes a piece look better, memory isn't accurate. I think its the concept behind the piece that makes stuff great so as long as your not directly copying someone elses work its ok.
using references for styles, elements, or subjects is just a way to develop your skills
for instance the art below is an awesome concept I found but the elements that make it up(color, line art, typography) are just apart of the style and can contribute to how to setup your art properly. I wouldn't copy the concept but the style is up for grabs.