Close range indoors practice is a great way to work on the little things that we often forget when outdoors on a 3D range.
I shoot a few dozen arrows at 2-3 yds only concentrating on one aspect of the shot at a sesion- release, anchor, back tension etc.
Other times I will put a piece of masking tape vertically down the bag target and focus soley on hitting the tape - this helps eliminate left-right misses.
I focus on very small spots- other arrow holes, dots made with a marker etc.
I can shoot outto about 12 yds in my basement.
Other times I'll shoot with the kids and play tic-tac-toe. I'm working on making a target face like a dart board, so we can shoot "darts".