Look for squirrels running up tree trunks or along branches. Watch for nuts dropping from trees and other signs that might pinpoint any active bushytails.
And a good pair of waterproof binoculars is handy to help spot distant squirrels.
Keep sound to a minimum, even when hunting from a boat. Wooden boats don't transmit nearly as much noise as metal boats. Banging a noisy aluminum boat might spook squirrels from long distances.
To cut down noise in a metal boat, place some carpet on the bottom. In addition, adding strips of rubber bicycle inner tube along gunwales may reduce paddling noise.
To minimize unnecessary sound when paddling a canoe, carefully and deliberately ease the paddle into the water. Keep it in the water as long as possible. Since sound travels extraordinarily well over still water, droplets dripping from a paddle can alert wary game some distance away.
In very shallow, hard-bottomed areas, use long paddles almost like push poles. Scull along without lifting paddles from the water. Also avoid rubbing the paddle, gun or anything else against the boat.