Originally Posted by: Gambitt

Every time the pick hits the low E string on an up-strum, it slightly moves, until after about the 3 strums it faces 90 degrees with the point facing down the neck.

[p]Rumble Walrus gave you some great suggestions, thanks!

Most picking problems are caused by one of, or a combination of, 3 things.

1. Too much tension.

When you first start learning it's complicated & you are focusing intensely on getting everything right! The natural tendency for some beginners is to use too much tension in your arm, hands, pick grip. So you have to make a conscious effort to relax!

This will help you strum in a more natural, relaxed, efficient motion.

2. Digging in too far.

The pick will fight you the whole way if you make it dig too far into the plane of the strings. Aim to barely, lightly graze over the strings. If you go down too far the strings will continually grab the pick & move it all over the place.

3. Ineffective picking angle.

It helps to tilt the pick so it is angled enough to make it easy to graze across the strings. You have to reverse this on the upstrum! This requires slightly rotating your wrist in between down & up strums.

I explain in this video on picking hand mechanics.

https://www.guitartricks.com/lesson.php?input=12189&s_id=605

Hope this helps!