Best tip... Dig it all! Relic hunting is different from coin hunting.
Yes you will end up digging some trash and nails, but it could lead to more goodies. Listen for large iron signals. That can be a horse shoe or barrel bands which could be a trash pit... A trash pit could mean bottles, bullets, buttons, etc.
If you find melted lead with a black ash, expand the hole, it could have been a fire pit and the soldiers sometimes tossed their trash into the fire. You could find bottles, buttons, bullets, j-hooks, buckles in fire pits.
Don't pay the screen of your detector any mind, if it's a good repeatable signal, dig it.