Dumpsters at the dump site.
Drives me crazy when we pack up to leave, put our full trash bags in the back of the pickup truck, and go to the dump site on our way out. Dump the waste tanks, and go throw the trash bags in the dumpster.... IF there is one! Preferably more than one (many times the dumpster, at places with only one dumpster, is full by Sunday afternoon).
Having dumpsters at the dump site is just such a logical thing to do, I just don't understand why some campgrounds don't do that. I've driven home with garbage a few times because we either couldn't find the dumpster, or I just wanted to get on the road home.
If the dumpsite is not in a convenient spot in the campground, then they should have more dumpsters strategically placed where needed in the campground.
It is important to have dumpsters or garbage cans easily accessible in logical places, to avoid people just throwing garbage on the ground (as too many do), or burning in the fire pit, or worse leaving it in the firepit for the next campers to find. Garbage cans should be by bathrooms, rec rooms, pavilions, etc. Recycling is great, but that requires the campground management to stay on top of keeping the separate garbage cans, well, separate - and emptied.
Having campsite garbage pickup is nice, but the few campgrounds we've been to that do that inevitably have missed garbage bags, or people leave them out too early, or the pickup crew comes at the wrong time - which all leads to full garbage bags sitting at campsites. Which leads me to believe that is why some campgrounds do the site pickup during the week - so bags aren't left out on the weekends, which doesn't look all that attractive.
At least one campground we went to had certain days and/or weekends where they allowed "large" items to be put by the dumpsters - appliances, furniture, etc. This is a great idea, and allowed the campground office to arrange with the garbage company to be ready to pickup more than just garbage.
With some thought, garbage disposal can be made easier and simple, and people will appreciate it.
(let's not get into the slobs that exist everywhere, you can't do much about that)