#1
Are there any specific exercises that helped to really clean up your alternate picking and make it more fluid sounding?
#2
No, but practicing with a metronome helps.
Gear:
Jackson Dinky (JB+59) > TC Polytune Noir > TS808 clone > DOD 250 > Modded RAT > CH-1 > GE-7 > TC Flashback > Plexi Clone
#3
Two notes per string isn't a problem at all but starts sounding dirty when going to a different fret/string for each individual note. Probably synchronization issues
#4
Then fix it by playing slowly first. How slow? As fast as you can while being clean. Now you have to be honest with yourself here; if you aren't clean, and you keep practicing that way, you will never be clean and it'll take a lot of time to fix that later on.
Gear:
Jackson Dinky (JB+59) > TC Polytune Noir > TS808 clone > DOD 250 > Modded RAT > CH-1 > GE-7 > TC Flashback > Plexi Clone
#5
Quote by gglenn13
Are there any specific exercises that helped to really clean up your alternate picking and make it more fluid sounding?

Practice.
Up and down every stroke until it becomes second nature.