With my ducklings, what I did was I just put a handful of food down near me and then they come near me to eat. Initially they used to get scared and were bit hesitant to come near me. They used to run away from me whenever I go near them. But, in about a week, they started liking me. After a while they started taking food from my own hand.

I would suggest you to just spend time with them, be quiet around them. And when it is feeding time, put their favorite food in a bowl and hold it in your hand or put the food really close to you. You need to sit with them, and occasionally pick them up and be gentle with them. Start doing these when they are a day old itself. In the log run, you will have a good result.