I use .22 shorts to limit the report, the squirrels don't spook and hide as much. Full camo is usually better, especially face cover. Limit movement, they have very sharp eyes. If you pick a spot that has plenty of mast all you really have to do is sit with your back against a tree and wait for them to come out, when you take the first one and the rest scatter just wait, they'll come back out if you sit still. I've shot my limit plenty of times that way.