Good questions, the most important thing is that you do it right away, if she bucks and you manage to stay on and only jump of a minute later - she will not know why she has to work. Of course, leave the tack on! There is no time to take it off :0) Have a stick with you too - trust me when you jump off right away and have the lead rope in your hand and swing that stick to make her GO she will not know if she has ever been lunged or not! It is not about perfect lunging, it is about showing her that if she does buck she gets to do something she does not like! WORK! Be careful with your body language too. Show her that you do not accept the bucking! Let me know how that works for you!