Hey 1jacko.wanne,

That is definitely a tricky skill and one that takes a lot of 'hit or miss' to dial in!

Just keep at it, create repetitive exercises for yourself like: 10 down/up-strokes with the pick on ONE particular string, in a row.

And then the same on another string, and another. 

That kind of repetition really helps the learning sink in to the 'body memory' part of your brain. 

Have fun! - Lisa