Just put some of their favourite treats in your hand, i.e strawberries and go half way towards them and they should come the other half because they can't resist treats, and continue to feed them out of your hand and then eventually they will just come towards you, and also what I do to train my ducks I sit in their run with them alot! and they just get used to me being there.
I can't get my hens to come near enough to take a snack. One loves peas, but she's not going to come near my hand to get them. Which is odd, because they will stop and let me pick them up to put them in their pen for the night or to get out in the morning....but other than that, they want nothing to do with me. Have held, talked, petted them once a day since I brought them home, but it's a no go. (Khaki's and Magpies).
I read (on another site) that ducks don't really like to be held. They equate that with being eaten. They don't touch each other except in mating.
My big ducks run to me. They like to hang around me. They will nap at my feet. They love to be at parties in the yard - particularly if there is a hose involved, and this seems not to be food-motivated. They will eat at my feet and out of my hands. They have never, however, appeared to like being pet. I have SO many animals that do, so I give my ducks space.
I have new babies now. I thought about conditioning them to be more pettable - but I did not take great time to accomplish this. They seem to be imprinting the same way - run to me when I call 'duck duck duck'. They eat at my feet, but when I move, they run away.
Among my big ducks are 5 mallards, so it is fun to call them and them fly to me.
I think my ducks love me even though they don't want to be touched.
Worms, worms, worms, and more worms. You shouldn't get them from a bait or tackle shop because they may contain chemicals (plus it would be expensive.) I dig them up from the dirtied guinea pig shaving pile and and as soon as they see them they run over and follow me around (my ducks once ganged up on the head drake for a worm.) This worked wonders with me since my mallards were rather wild acting since they were babies. Hope this helps!