The first time I let Henry off the lead he vanished off into the woods and I almost had a heart attack! I have spent the last 7 months hiding behind trees, bushes, clumps of grass, and have definitely been mistaken for a flasher or someone having a wee at least once
BUT he has learned to keep an eye on me because I could vanish at any second and take the biscuits with me
I also use a whistle - unless there is something really exciting (like a rabbit, squirrel, or lump of foxpoo) he will now come back.
I have also found playing games helpful, he doesn't bother about toys when we're out but he does love it if I throw stones into the undergrowth - he leaps around like a numpty, normally in totally the wrong place but he does have fun pretending to be a proper working dog and he knows that it is me providing the fun so comes back for more! Sometimes he even finds them, in which case he gets an extra huge fuss once I have picked my jaw up off the floor (I really don't think he's too bright, good job he's pretty
)
He now stays in sight most of the time. I have also put bells on his collar sometimes so I can keep an ear on him - I will be using these in winter in the dark.