It's been really interesting to read all the different feed practices. Very informative. Seems like the "best" way is dependent upon a variety of factors.
I'm very new to chickens, so I am still experimenting to find my best way. Right now, I think I fall into the mixed camp. I do offer feed all day, but I fill the feeder daily with only a little more than I expect them to eat that day. Took a bit of trial and error to pin this down and I suspect it will change at they get older and start laying. My chickens have not been without food at all since I brought them home. I pick the feeder up, with whatever is left in it, and put it in their coop with them overnight to keep the mice out of it. They will usually have a snack right before they go to roost. This also allows them to access food before I get out there to turn them loose. They get up about an hour before I do this time of year.
Since I feed Scratch & Peck, which is a mixed feed instead of pellets or crumble, I find that I have a lot of fines left in the feeder each morning. I use these to make a mash with warm water each morning which I serve as breakfast. I then refill the feeder and set it out. The chickens prefer the mash over the dry feed and eat that first. The mash is usually gone by lunchtime, at which point they switch over to the feeder. Of course, they don't eat any of it non-stop. They fill their crops, then spend some time bathing and preening while the crops empty. Then they go out and forage a bit, then hit the feeder, then back to resting. Repeat throughout the day.
I am not letting my girls (and two guys) free range much yet, but they do have a largish run (300 sq ft) to forage in. I let them out for short, supervised ranging every now and then, but don't want to do that too much until after they start laying. I want them to get used to laying in the coop rather than hiding their eggs in our landscape. We live in the woods and most of our 2 1/2 acres is natural with lots of places to hide those precious butt nuggets. I don't fancy a daily egg hunt through the underbrush.
We also have a lot of predators, which is another reason I don't just turn them loose every day. Plus, our neighbors also have chickens and I don't want mine wandering over to visit. My hope is to get them to where they have some free-range time every day, but we aren't quite there yet.
For now, I occasionally dump yard trimmings and buckets of dirt into the run for them to dig through. I also offer kitchen scraps as I have them, mostly fresh fruits and vegetables, though not in huge amounts. I've noticed when I supplement, their feed consumption does drop, though not drastically. They all look amazingly healthy and we have had zero health issues since I got them (
*knock on wood*).
me thinks it's enough ... Haven't had any problems with keeping chickens over the 20 years, 
BUT I never had strictly Leghorns , and they are small and lay so many eggs. Just wanna make sure I'm doing right by them 
..... So I REALLY appreciate the advice and you all!!
