When my pick passes through a string and rest on the string below should the pick be resting flat on the string? In other words the plane of the pick, not the edge of the pick resting against the string. I have tried picking with the pick at a 45 degree angle and I can not seem to rest properly. The pick will move or slide on string intended string for resting causing me to tense up. I think I am misunderstanding something basic here.
It could be you´re using too much force or tension in general. If you really hold the pick right and just let it fall through, the impact usually wouldn´t cause the pick to turn and rest flat against the string. Try to focus on the fact that the hand should completely relax once the pick touches the resting string. don´t care about getting the right resting position, but just relax.
I´ve found the pick tends to move and change the angle when you hold it too much towards the tip of the thumb. Getting closer to the joint fixes the pick better. The 45 degree angle (not to be taken literally as 45 degrees, any angle makes the difference from "flat against the string") should come more from the hand position than from the way you hold the pick.
When I started with this technique I found that there´s hardly a chance to see the subtle details through without going really slow first. I had the metronome at 50 BPM and would play downstrokes every 2nd beat. It really took that long to give the "play and relax" procedure full respect and awareness.
Hope this helps you, good luck !
Working for a while on your pompe will get you ready to gypsy pick.
Hand position, pick grip, motions... it's pretty much the same but on a smaller scale
As Matthias said work really slow at first, that's the fastest way to learn: Slow.
they have lots of pictures explaining the angle of which your looking for