I use the scope to help me. At 8 yards I cannot make out detail of pellet marks even if I squint. So 8 yard aim point in the bottom. At 10-11 yards I can just see detail so I put the 10 yard in the bottom.
Try and find little tricks like this with your kit. Can you bracket the kill? You should be able to see an 8 yarder by eye with a bit of practice. Then hedge your bets.
For practicing positionals get up after each shot so you practice getting into position as you would in a comp. Don't panic, the close ones will get easier as you learn from your misses. The positionals Will slowly improve but are the key. imho to high scores.