How on earth do you avoid doing that?
(Assuming that, like me - and incidentally also like the legendary neighborhood 250-scorer RangeDog - you must point your support foot directly at the deck because your legs are too inflexible to allow pointing that foot sideways, and your enablers of kneeling position ahem, boots, are too sturdy to allow pointing that foot rearwards by planting those laces on the deck.)
I have the same issue when I'm wearing my tall boots. I just point my toe as much as I can, and relax the ankle.
I always shoot better in sneakers. Partly because of this.
I assume you all are talking about the prone position. The only way to lay your foot flat on the ground, as stated in the IMC, is to turn it sideways, to either side; not lay the laces on the ground. If you have an afflicted leg which might prevent this, or boots which may not let it lie completely flat, still turn it sideways as much as possible and relax the ankle. If the heel is straight up, it will still give trouble by having a tendency to wobble. Roswell has the answer. Don't wear restrictive boots. Wear tennis shoes or sneakers.