Never done the boot carry thing, though I do wear them. Do you use an ankle holster, or just stuff it in your sock?
FQ13
I'm right handed (important fact in this description):
A right hand iwb with an added retention strap (I took an old Uncle Mike's and added inch and a half wide velcro - hooks on one side and loops on the other) ;
Clipped to the inside of the shank of the left boot;
Draw consists of planting my left foot; grasping pant leg at mid calf; rocking back and dropping onto right knee. This motion brings the pant cuff above the boot shank, and my right hand is right next to the gun. A quick rip of the velcro, grab and draw.
With practice you will find that you can quickly and controlled drop to the ground with your left calf and right thigh perpendicular to the ground, your knees will both be bent at ninety degrees, and your left thigh and right calf will be parallel to the ground. This will give you a very solid, stable and compact shooting stance, while allowing the flexibility to rotate at the hips to scan left and right far enough to get a full 360 view.