It matters not the age of your pup or dog, but the sooner you begin to teach your companion the recall, the better.
Let me begin by stating that I've seen more pups and dogs lately that have been taught the "anti-recall"... with owners cheerfully bragging how much their beloved dogs just LOVE the "chase game" !!! This is a bad, bad game, and teaches your dog to run FROM you, rather than TO you. In principle, this is bad, and can truly be a dangerous and life threatening habit for your dog, if it should slip out the front door and towards a street.
One can start teaching a reliable recall by remembering a few important points:
1. NEVER EVER EVER punish your pup or dog for coming to you. EVER.
2. Do not ask for a behavior that you cannot reinforce. (This applies to all training) In order to reinforce your pup/dog, you must be attached to it. So, have a 6 foot lead, a lightweight long line (laundry lines work great with an inexpensive clip attached) on hand, and plenty of treats and a favorite toy.
3. Use "formal" commands for behaviors that your dog MUST comply with, and informal commands when you cannot reinforce the behavior 100% (i.e. "Come" means you come to me no matter what... "Come along" or "Come here" might allow the dog to just come closer to me.)
4. Use correct timing for your praise/reward. You have less than 2 seconds to reward your pup for offering you a correct behavior. Be quick, and be correct about WHAT you're rewarding.
By the same token, you have less than 2 seconds to correct your pup for a wrong behavior. Something to keep in mind.
5. Keep all training sessions very short. A few minutes at the most, but if you receive an unusually wonderful response, end the session right then and there. It's good to remember, that your pup is very smart, and they remember everything they learn... so if you always end on a GOOD note, it's the quality of the session that's much more important than the quantity of time you're taking up.
To begin the recall training, start with the shorter leash. Let the pup wander around at the end of the leash, then call the pup's name, and tell it "Come". At the exact moment that you utter the command, give a slight pop on the leash, and move backwards in a happy, receptive manner. As soon as the pup has made it to you, reward verbally and with a tasty tidbit at the same time.
Rinse and repeat. Perform a happy dance with each quick and correct execution. Before too long, your companion should not need any further prompting with the leash.
Once your pup is offering a solid recall on the short line. It's time to generalize the behavior. Practice this with the longer line in the same environment. Practice at a park. Practice with a short lead in the vet's office. Practice in the grocery parking lot. Take cookies to your local Fire Station, and practice in their parking lot. (get the idea?).
Practice makes perfect.
Once you have a reliable recall on lead in several different environments, begin at home again off lead. Start with a VERY short distance (remember, you must be able to reinforce what you're trying to teach!) Practice in the backyard, then, once your friend has bat 1000, try it in the house around corners and such.
Remember, coming to you should be the MOST FUN THING your pup can do. This helps to promote your pup paying attention to you, and you both will reap the rewards of having a mutually happy time together. You'll spend less time being frustrated with a dog who thinks it's fun to run away from you, and your dog will thank you for it.
Any questions?