Used to look for arrowheads as a kid when fishing Pymatuning Lake on the shore of Clark Island and others. Used to find them occasionally. I always sort of keep my eyes down, out of habit, and I will occasionally find things. Best time to look for artifacts is post rain - washes some dirt away so you can see things on the surface more easily, although that doesn't necessarily make the fishing better.
We used to ask farmers to walk their freshly plowed fields in the early spring in Western PA, and would walk the rows after a rain. In certain fields, we would find 20-30+ intact arrowheads, occasional tomahawk or spear points, and lots of flint/broken arrowheads. Other fields would be a complete bust sometimes. The best fields to target were those located by creeks or rivers where native Americans likely had set up camps in some sort of strategic location.
When I walk larger bodies of water that probably used to sustain frequent canoe + boat travel, I always keep my eyes peeled on the banks. Especially where smaller creeks enter the larger bodies of water.
My father used to read a lot of local history books about native Americans, etc. and he would use this information to take me to areas he thought might have artifacts.
