Generally speaking, whether you hunt the gray or fox squirrel, you'll be dealing with three distinctly different seasons. Where seasons open in late summer, you'll be faced with trees in full foliage, making it tough to see squirrels. However, the bushytails will be extremely active gathering acorns and nuts. In areas where hickory and oak trees grow in the same forest, look for trees with bright yellow leaves. These are apt to be hickories, which commonly turn color before oaks.
Squirrels often focus on hickory nuts before they begin working on the acorns produced by oak trees.
Listening is a big part of the strategy when squirrels are feeding heavily. On a quiet day you can hear them husking nuts, and, if you're intensely observant, you can see bits of shells raining down on the forest floor. I like entering the woods early in the morning and taking a stand near several mature trees laden with nuts. I remain still and wait until a squirrel appears. If hunting pressure hasn't been heavy, I'll let the first squirrel begin feeding and wait for more to appear.