There are a couple of ways but the key rule is to always be more interesting to your puppy than whatever may prevent them from returning to you (ie: if you are out walking you will have to compete with all the wonderful smells). Having a favourite treat is probably the easiest way to be awesome in your dogs eyes. In my puppy classes I will even tell the answers to dance around the room and make a fool out of themselves so as to keep their puppies attention on them. After this exercise, by the time they call their puppy to come, the puppy can’t wait to go and see their owner! Unfortunately not everyone is willing to play the fool for their puppy but the ones that do get results everytime.
The easiest way to begin is with the help of another person (but if you can’t make sure you are in an enclosed space during the early stages of this training). Ask them to hold the dog on the lead (so they don’t wander off) and take a few steps back (not too far), call your dog to you ie ”(insert pup’s name) come!” and as soon as your puppy comes to you, give them a treat. Keep doing this but gradually increase the distance between you and your dog.
If you are in a field or open space create a game with your puppy by encouraging him/her to chase you. This will make you really exciting in your puppy’s eyes and if your dog thinks your exciting/have something to offer then they will, more than likely want to return to you when called.
A top tip when practising recall is to not always put them back on the lead when you call them in. This will only make puppy associate the recall with the end of something fun so make sure that, during your walk, you call puppy in a lot, give them a treat and then let them carry on exploring.