RE: Squirrel calls
If you want an effective call, start practicing with your voice. A little practice and you can develope a very realistic call by voice. If you have local squirrels in your area, listen to them, try to imitate their vocals. I have a couple calls that just gather dust, none of them actually sound right. In fact most squirrels hide when you blow them.
I've called squirrels in for over 100 yards, and mimic a squirrel has gotten me at least two deer that had spotted me. When I give a couple barks, some even returned near my stand and gave me a perfect shot. Besides that, when you get the hang of it, you're call is always with you.
Russ