You don't have to wear yuppie scum gear from Territory Ahead catalogue like some of our yuppie scum TFLers, but you should shave, wear clean clothing, tuck in your shirt and pick up your brass. Set an example for others around you and they will think it's a rule and do it without being told.
Gomez, the only way to turn range slobs around is shame. Whip out a trash bag from your range bag and say "here, I'll help you pick up your rubbish." Some guys just think they can leave their garbage around because "everyone else is." Geez, what is this? The Army?