I download and print off targets, and take a selection to the range so I always am shooting at a unique target that no one else is using.
I did get somewhat accused of shooting at someone else's target back in the spring. I showed up to the range, there were 3 older gentlemen there already shooting. They went cold, let me put up my targets, then the range goes hot and we start shooting. After about 10 minutes one of the older men yells "Who's hitting MY targets" and gives me, the younger new guy, the stink eye. Wasn't a chance it was me, I had only been shooting at the 50 yard range up until then while he was set up at 100 yards.