For animals, the trick is SLOW. Every movement, every action must be done slowly and calmly, no rush. And watch the animal, Move up in increments, don't rush in. If the animal tenses or looks like it is about to bolt, stop, ease back a little and wait until it relaxes again. And keep a low profile, even if it means crawling. Get a tree behind you, whatever, to help camouflage your presence. But most important - CALM, SLOW MOVEMENTS.