Best advice I can give you is to practice in burst.

Instead of going up and down the fretboard, start by making little burst of three notes. Focus on precision and speed. Don't try to play too fast otherwise you'll end up with sloppy techniques like me :)

When you can play three notes burst really fast (when you think you're good at it) add one note, then another and so on.

You'll see how much your skill will improve but never loose sight of your precision.

Practice down the scale then up the scale then both.