For babies - spend time.
My little one walked over and sat in my hand when I went to take them out this morning.
I bring them in to play in the bathroom until I know they will follow me outside. I sit/lay on the floor to let them get used to me. I put the brooder up so I'm not reaching down to them, but in. My brooder now is sitting up on saw horses so I don't have to reach down to get them.
I've also brought them in and put a towel on my lap and just sit with them. I only have 2 this time around, so I bring them both in together. With more, I'd do one at a time, or 2 at a time.
When I put them back in the brooder this afternoon (they spent the day in the turtle pen), I leaned in and one climbed up on my arm and sat down then curled up on me. Then the 2nd one joined.
We'll see what a few weeks bring when I turn into the devil in their mind...
But time. Let them get used to you and then just spend time with them.