I just use the leash. That way the dog is never more than 6 ft away from me and I always have the other end of the leash in my hand - that way there can never be a "misunderstanding" against my dogs saying they were uncontrolled.
I tried the tie outs, but found that it was more stressful for my dogs because there was always some idiot who let their dog(s) run around free and that dog(s) would antagonize my dogs by standing just out of reach and peeing...
With the leash, the dogs are always right with me and I can easily move them away from a potential problem.