How do I stop files piling up on my Mac desktop?

I never knowingly save files to my desktop, and yet they gravitate there as if to a black hole.. Today I mistakenly clicked what was evidently a stack of files and they covered my desktop several times over. I couldn't read individual titles because they were overlapping many times over. I've seen suggestions that iCloud has something to do with this but I rarely use iCloud. Is there a way to stop this happening?