I struggled with this for a long time. I was just impatient with my set and kind of afraid of the height! What helped me was to go with 8-counts, with 1 being when my hands hit the ground in my roundoff. Your set should start at 5. I told myself, "you can't tuck until 7." So I'd go,
Run 5-6
Hurdle 7-8
Hands 1
Feet 2
Hands 3
Feet 4
Set 5
Freeze 6!
Tuck 7-8.
It forced me to spot in front of me and wait before I tuck. It was hard to grasp at first, but you can always try it on the tumble track, with a spotter, etc so there is that wiggle room. Once you get it down, layouts and beyond become so much simpler!