-If it's very hot where you live, changing the water daily is helpful because chickens often like cool water so it encourages them to drink. Mine always visit the waterer right after I change it on hot days.
-I give them a few black oil sunflower seeds (BOSS) with a little scratch at treat time, since the oils are good for them.
-I don't mix scratch and feed because I want to make sure I can monitor that they are getting only a very small percentage of scratch relative to their feed. I scatter a little scratch in the run when I want to call them back from free ranging. I stop the treats fairly early in the day so they will fill up on their healthy feed before bedtime.
-I store feed and scratch in the 25-lb airtight plastic dog food bins that Target sells. But I keep those bins indoors; use something different (thicker plastic or metal) if you are storing outdoors so rodents don't chew through.
-I feed them an organic brand called Modesto Milling; I know someone who has a seven-year-old Polish who still lays and has been eating that brand her whole life. It's the same feed all year, but I have very mild winters so others might do something different.
-I got my pullets at 10 weeks and made grit available right away. I then changed from chick grit to layer grit as they got bigger. There is always grit available (I order it from a company called Scratch and Peck), but they don't use it anymore because they have free range time every day.
-For treats, they like scrambled eggs, yogurt, dried mealworms, kale, chard, and apples (I have an apple tree and they enjoy rolling the fallen apples around and pecking at them). Chickens vary in what they like -- some people say theirs won't go near yogurt, and others say their chickens love stuff that mine won't touch (like watermelon).
-I have only laying hens, who get layer feed and also free choice oyster shells as a calcium supplement. The yogurt is good for that, too.
-Mine don't produce those super orange yolks, and I asked about that a while back on this site, and someone posted that she thinks it's actually a breed thing -- all her hens eat the same stuff, but her Buffs lay orange yolks while her other chickens don't. I think some feeds have marigold in them to color the yolks.