Microchipping helps. The first thing I teach my dog is re-call.
Start by calling in the house, when he comes make a big deal and give him a treat and walk away. Make it a fun game for him. Do this a few times til he get's it perfect, then do it outside, in a fenced yard. He will soon learn, when he calls me I get a treat, and will go about my business. Don't ever catch him when he comes because he will say "Im not coming because you will catch me and my fun will be over". When you have another moment like this call your dog, and make sure you use the SAME tone, not mad, worried, or frustrated because he will know something is up right away. Then he won't see it coming, call him and when you act like you treat him grab his collar.