Alright... I'm fairly good at it so here's a few tips
1. Do your scouting and have a plan (and stick to that plan)
2. Choose the right weapon - It may not be practical to use your scoped 17 hmr on squirrels running at 20 yards as its will not be as practical to use your 12 gauge when you are estimating an average shot of 45 yards or greater. (Ps, tried it with a long bow last weekend and its awesome fun)
3. Be patient - Contrary to what I've read in some books a lot of how squirrels seem to track you is when you move. If you miss then don't move because he may come out to investigate. Also when moving into an area after day light (reds in my area really start cutting between 9 and 10 am) move slow and be looking up for em. If you slow down and really scan you're going to pick them up sooner.
4. Practice your shooting before going out there. A lot of hunters don't give squirrels credit and they can be smart hard to hit little F**K*RS. Be sure to practice.
5. No more than 4 people. In fact fewer the better.