Have both dogs on leash but keep the leashes slack, as tension on the leash transmits tension and anxiety to your dog. Do not have one dog on leash and one dog off: this creates a huge imbalance and adds lots of tension.
Walk the dogs parallel to each other for a short while, gradually getting them closer to each other. This allows them to "air sniff" each other and get comfortable before the actual introduction. Do not have the dogs meet head-on, since in dog lingo face-to-face approaches are considered rude and abrupt. Do not stand and stare as you introduce the dogs, as this creates a tense atmosphere. Humans should keep Moving !
If one dog is more apprehensive about the meeting than the other dog, allow him to approach the other dog from behind and sniff under the other dog's tail first.
Stay relaxed. Breathe. The more relaxed you are about the introduction, the more relaxed your dog will be. If you tense up, your dog will get the impression that he needs to protect you and himself from the new dog and human. Stay Relaxed and Breathe !
Keep moving! If you and the other human just keep walking chances are good that the dogs will happily walk along and check each other out in a comfortable, casual way.
Please remember to keep an eye on your dog at all times. Monitor his behavior and step in if you need to. Always take responsibility for your four-legged friend . That way both dogs and humans can enjoy an outing at the park.

Dog Introduction Tips