I often hear my clients say that they are afraid to walk their dogs off leash in an un-fenced area. They fear that their dogs will run away. Mind you we live in an area with miles of beaches and trails that are open to unleashed dogs, basically dog heaven. Meanwhile, I walk these same dogs off leash very happily with a few caveats.
The biggest mistake people make with their dogs on walks is not walking far enough. Most dogs are energetic and adventurous, they can easily walk/run a mile or two.