How to tame your chicks:
I posted this on another thread when someone asked how and when to handle her chicks. The warm air in the 'egg' thing really works:

Start with a small brooder so that you don't have to 'chase' the chicks with your hand to pick them up. Talk softly while you are approching the brooder, move slowly and put your hand in slowly, palm up.

Slip your hand under the chick's tummy, cup your other hand over her and lift her gently to the area of your chest just under you chin. You want your hands to sort of form an 'egg' around the chick with her head sticking out. NOW THE IMPORTANT PART: Allow warm air to envelope the area around the chick in the 'egg' formed by your hands by putting your mouth just above the chick's neck and using sort of a really slow, open your throat 'haaaaaaaaaaaah' warm breath. They tend to relax immediately. When they relax and sit down in your hand, you can then use your thumb or forefinger to gently stroke the area behind the little ears and back of the neck. They learn quickly that your hand is a good thing. Do this several times a day with each one. They also like the feeling of being snuggled up to your neck where your large blood vessles are (so they can feel your heartbeat). I talk to mine in a low, calm voice when holding them there.

If your brooder isn't small, try this trick to lure them to your hand; make a small dark dot on your palm to entice them to come 'peck the dot'. Once one starts, usually several others will join in. It becomes a competition for them and before they know it they are gently lifted off the ground. I don't use real food; I prefer that they learn from the start that 'hands are for loving'. When I was little, I remember my mother telling me not to handle the chicks; it would make them sick. I'm not sure but I think I was an adult before I figured this out. It works best if you can start with less than a week old chicks.
So its OK; you can handle your chicks - just be gentle -they're so tiny....
Or if they are older or adults:
Sit on the ground; I use a towel.
Gently toss the treats near you but just out of your reach so the chickens won't be afraid that you are going to grab them. Talk to them quietly while and after you've given the treats.
The next day and a couple of days after, put the treats just within your reach but don't try to touch the chickens.
Then hold the treats in your hands the same distance as where you placed the treats the day before. Several of them will take the treats from your hands, some won't.
Don't put the treats on the ground! Only let them have them from your hands so they know they have to be near you to get a treat, and, not think about it too long or another chicken will get all the treats and they won't get any!
After most or all the chickens will take treats from your hands, offer the treats from your hands with your hands resting on your lap. A chicken or two will get on your lap for the treats. Do this every day without trying to pet or pick up the chickens. Some will linger after treats just because they want to be with you. Those are the ones to work on taming.

When you do try to pet, only do it from the underside of the chickens-not the back (they'll think you're a predator). Always be slow and consistent. They will come around.