DO ask before you step in anywhere close to someone on the water. Politely approach behind them from their non-casting side and ask how they’re doing and if it’s okay if you fish where you intend to. If they don’t answer – move on!
DO let another angler know if you have a fish on and need to enter into their space. Of course they’ll say it’s alright and will probably offer to help you net.
DO get out of the way if someone has a fish on in your area. Just reel up your line, let them do their thing, and offer to help. Try not to be too jealous.
DON’T be rude, period. Fishing is supposed to relieve stress, not induce it.
DON’T step into the water where someone is fishing.
DON’T let your DOG run into the water where someone is fishing.
DON’T assume it’s okay to fish just because a person is sitting down or standing without a rod. If a body is just surveying the water or eating a sandwich at the water’s edge – that’s their water for the time being