Best EVER fly trap!! Add a cut up hot dog and a tablespoon of maple syrup with about 2-4 ounces of water to a jar with a lid. Poke a few holes in the lid...(big enough for the flies to easily enter) and believe me, they're too dumb to find their way out!
Homemade Cheap Fly Trap - I prefer the jar style. You could make the top one with cardboard instead of wood. You could use a large plastic container and cut large windows in the sides and tape or glue old nylon hose pieces over the windows.