I spend a few days before working in rubbing their ears at meal time. Come tagging day the majority go in with no fuss.
However, if You're doing weaners, I'd get them in a confined space. For example, trailer or arc. Sprinkle some food and then grab.
Practice makes perfect - we found tagging difficult for our first couple of batches to go off but now I do it the night before or in the trailer and think nothing of it.