You'll make more progress if you don't pick them up but bribe them into coming to your hand. Try to approach them from their side or below rather than above, as coming from above sets off their instinct to avoid predators. And yes, some will respond better than others. I have chickens who walk right up to me (looking for a treat) and others who won't come near me.
when the sun goes down and they are wanting to sleep, while it's dim, don't turn on a light, take and hold 1 or 2 at a time, this should make them want to relax with you, they can't really see you well and they can't resist wanting to get cosy in your warm hand. Good luck!
