Biggest tip: NEVER GIVE THE COMMAND COME UNLESS YOU CAN ENFORCE IT. The dog should never see it as "optional". Responding to this command could save his life someday.
With a pup that age you can attach a long piece of twine to his collar. Get around in a big circle, include all members of your household. Give every person a pocketful of really good treats. Take turns telling the dog to come, make it very enthusiastic, pat your knees, whatever it takes for the dog to voluntarily come. If the dog does not come you can give a
gentle tug on the twine, but you probably won't need to. Praise and a treat each time he comes. Do this every day at least.
Everyone in the household needs to learn this routine and should be taught never to tell the dog to come unless they follow through. That will be forever.
Tip#2: NO MATTER WHAT THE SITUATION, IF THE DOG COMES TO YOU WHEN HE'S COMMANDED TO, YOU NEED TO PRAISE. That means even if the dog was chewing your flower bed and you call him to come (just an example), you need to praise him for coming. **Never scold a dog when he comes to you** or he will learn that coming to you gets him scolded. Coming to you should always be a pleasant experience if you want it to work when you want it to.
My previous dog, Kayla, never knew she could run away from us if she really wanted to. Her entire life if you said come, she came, no matter what she was doing. We used the above methods when we first got her as a pup. My current dog is good with come as well, luckily, but it's been more of a challenge since we now have young children and they will tell her to come but not enforce it at times.

I've included the kids in her group training and they're really doing a good job, but consistency with training is really important. Good luck.
