I have had my oil changed by others one time in my life, that was a free change by the dealer. Well when I got home the dipstick was way over full, the idiots put in too much oil. Took it back and they still got it wrong. Never again!
I do check the oil after I change it, but on my 6.7 Ford diesel the cable type dipstick is about useless till it sits for a day. Then I get one chance to check it because the cable drags oil up the tube and subsequent checks are again useless.
I have a pit in one garage bay, so changing oil is easy. When I have a few changes in my oil waste collector, I take it to an Amish farm where they burn it to heat the barn.