Try popping your arms forward a little bit at a time. So instead of trying to pop your arms out as far as possible (which will get you the best looking headhollows), try only doing it a little bit in front of your head. Then slowly work your way so that you pop out more and more. Hope this helps!
Its a strength move..When you get to your Hollowback...Push as haaarrd as you can down on the floor with your hands make your u really feel it on your triceps for 15 seconds..than release..and repeat that 3times...Sooner or later you will be lifting your self off the ground, i cant do it but thats how you can work your way up to it
It is all in arm strength and balance, to practice on that or to even attempt it try learning to hold basic and or( Recommended but not necessary) a one handed handstand will help a sufficient amount.
Sorry this is super late! I would work on just getting a headstand first. Practice by just putting your head and your arms in a triangle, then slowly putting your knees up, then extending. After that, you can start working on the headhollow :) Goodluck!
do you eventually get used to the pressure on your head, or is it painful every time? lol cuz i've been practicing head spins and head stands on cardboard but its still painful.. so i cant imagine what it's like when people do it on wood or something :P