I don't have a trailer to back up, but just a longish class C that is not the most maneuverable or convenient vehicle to get into a tight spot.
I'd much rather have people snicker and suspect that I'm green behind the ears because I get out and look every three feet and maybe need to make a few passes before getting into position, than to boldly back into the corner of the picnic table and remove any doubt in the matter.
It's a pretty safe bet that most all the onlookers were once new at backing into a campsite (if indeed they aren't just as new as you are).