Introducing my Chickens to free ranging

I have 3 chickens (2 hens / 1 roo) I would like to let them out of their pen for a little while. They've been with me for about a month, and I'd just like them to have a tad more freedom then the run I have, but supervised.

Can someone give me some kind of pointers so

#1 - I have all my chickens after free range time.

#2 - no one runs away, they're still skittish around humans.

I was planning to do it closer to dusk, because my 🐥 are really good at putting themselves to bed about 15 mins before the sun goes past the horizon, but I also don't want to be chasing chickens in the dark.