Does your dog know his lefts and rights? This is an easy trick to teach. When you take him out on a leash, does he tangle it around your legs? It may be useful to tell him "Left" or "Right" and keep yourself untangled from the leash. Not only is this a good trick to show off your smart dog, this is a useful command that professionally trained assistance dogs are expected to learn.
Step 1: With your touch stick, have your dog go around your right side and stand by your left side. Click and treat. Step 2: Keep doing this, eventually saying, "Left" as soon as he stands by your left side. Step 3: Repeat this action until he no longer needs the touch stick and can go to your left side at your command. Step 4: Do the same thing, this time teaching him to go from your left side to your right side.
When teaching Caspian left and right, we began by using the touch stick. We would motion him to both sides, and clicking/treating. However, he easily became confused, and didn't quite get what he was being clicked for. Sometimes there are more than one way to teach a trick, so what we ended up having him first sit, then we would turn around, and pat our leg as to which side we wanted him to go to. When we motioned with our hand, he would come to that side. As he did so, we would say the command either 'right' or 'left.' We then started just saying the command, and leaving out the hand motion, and only clicking/treating for a correct performance. We would mix up the commands, just to see if he really knew the difference between right and left. Using the touch stick is a great way to teach this trick, but you may feel the need to tweak the steps a little to suit your own needs.
My dog is getting his left confused with his right! What do I do? Try treating 'Left' and 'Right' as two separate tricks if this is happening. Usually, you want to teach both left and right so that your dog can differentiate between the two, but if he is getting easily confused, start with one, then move to the other. Try focusing on just one of them per training session. Hand cues are also important here: If your dog is paying attention and wants to find out what you're asking him to do, he'll look for hand signals, motions, or a direction from you to point him where he needs to go.
Tip: "You can gradually stop using the touch stick by guiding your dog with big hand motions. Then, you can make your hand motions smaller for a polished performance!"