All of the birds I have used shackles on(Red-tails,Harris) I have used shackles on the perch in the jeep,Then I would undo the shackle on the jeep perch and shackle them on my glove to the jesses and go to the field. Then I would undo the shackle from the jesses and hold the jesses till I decide to let go on a slip or just let the hawk be free to go in a tree or sit on the glove and hunt. When it's time to go home I get the hawk on the glove and shackle and back to the car perch we go.This is with a hawk that is trained and one that is calm. That is how I do it. It works for me,others might do it different. You will find that other falconers with have there own way of doing things. You should follow what your sponsor's way of doing things first and when you are not a apprentice any more and know what you are doing in the world of falconry then you can change some things you have learned and see if they work for you.