Puppies are the easiest to teach recalls to, and they are wonderful liitle learners. With puppies, I take them to a safe place, perferable a baseball feild at first and play come catch me games. I run away from the puppy and let the pup chase me, when the pup catches me I play with the pup. Rewards are lavish. Pup's love this game, unfortunately most people have this desire to chase their puppy
this is going to teach the pup a new game, or play avoidance. It's a natural instinct for the pup to run away from the chaser...it then turns into a game and can become a hard thing to train out of the pup. When the pup gets used to the catch me game, I then start playing with the pup, if the pup gets far ahead and starts sniffing something I use this as a valuable training tool, I walk past the pup with out reaching for the pup and ignoring the pup. The pup soon learns that every time you walk toward him/her they are not going to be put on a leash etc.
Once I am comfortable that the pup loves to come to me, I then venture for a hike in the woods with little distraction...or I take my dogs which have reliable recalls...a pup learns a lot from adult dogs...they watch and imitate what the older dogs do. I play hide and seek games with all puppies I take out (my friend breeds, so I take all her puppies out). Hide and seek teaches the pup to keep the human in sight at all times. I love this game, when the pup finds you you can either reward with lavish praise and roll around playing with the pup, or lavish praise with food rewards.
This same method has worked wonderfully even for my 2 rescue dogs one of which was a feral dog. I live out in the country and own 5 dogs, I have to have a reliable recall...there is no way I could enjoy hiking with 5 dogs if I had to keep them all on lead...that would be really bad experience. Make your pup "want" to be with you and they will never leave your side.
If you want to pick up some books on early puppy learning...pick up anything by Jean Donaldson or Dr. Ian Dunbar.