Robert, I didn't read all the other posts here yet so I'm just gonna throw a few things I do at ya.
I have a corn cob feeder screwed to one tree on one side of my yard. I smear PB on a used corn cob. They love that crap!
I also have a bait tray in the back on a fence post amongst some small trees. In it I use old bread, popcorn, fruit, veggeis, biscuits, etc.
Squirrels will eat almost anything.
You can use nearly any type of cracker or bread product. Even pizza crust.
They will raid bird feeders but that can get costly and wasteful in a hurry.
If they see you, I suggest finding or creating a blind or barrier to block their little beady eyes.
Often, I drop the blinds most of the way down and move back from the window a couple of feet. This also muffles muzzle noise and they have no idea where the sniper is, Ha!
