How do you safely capture a lost dog?

Does anybody have any advice about what to do when you find a non-aggressive lost dog? With July 4th approaching and Humane Societies in the U.S. reporting that there are more lost dogs on this day than any other of the year, this would be valuable information. Late the other night, I found a wandering Beagle. I had dog food in the car and he came within inches of the food and then went roaming off. I tried to follow him but lost him. I called emergency services and they said they'd keep an eye out for him. Luckily it was a very quiet area without traffic, but I don't know how far he went and the sweet dog keeps entering my mind. He was friendly, but he was intent on following his nose and I really hope it lead him to his family. I'd like to be more prepared on July 4th, just in case it happens again. Last July 4th I found a wandering dog and fortunately I was able to put a leash on him and the story has a happy ending. Any advice would be appreciated. And please make extra sure that your dogs are wearing ID tags at all times this holiday weekend.