When I had mealworms or BOSS to give as a treat I would put it in a red solo cup and as I was approaching the pen I would shake it around a little. Well evidently I was training them! A few weeks ago when we wanted to put them in the fenced unplanted garden to forage etc. I opened the pen, gave them a tiny bit and let them have a tiny bit from the cup, walked towards the garden shaking the cup and they followed me across! We can't let them free range due to neighbors and predators (dogs & cats). At dusk we repeat the process. My husband did it the other day and it sure was cute to see him walking the chickens!
edited to add: once I get them where I want them I give them a little more as a reward, so it's not like I'm teasing them!