The pick or plectrum. Experiment with lots of them.
Type .73 seems a good overall thickness.
The material makes a difference. Nylon is highly flexible. Tortex hardly at all, therefore when the strings are struck there is different feedback through the fingers.
Shape the standard rounded elongated triangle is the best starting point then experiment
with the myriad other shapes.
Holding the pick . Thumb and index finger is the most common. Hold it lightly do not griphard. Relax. Thumb and middle may be better for speed metal.
How much pick. 50/90%covered by the thumb Strumming 50% Speed metal 90%
Pick angle on the strings. Single notes.
I prefer the pick to be perpendicular to the string (The tip of the pick is at a right angle to thestring) the pick can be tilted forward or back (same angle either way) When the pick is flat/perpendicular to the string the area of contact is greater than when angled . The attack istherefore different when angled and the area of tip contact diminished. This can be better for speed picking which also involves escape angles.See Troy Grady.
Hand placement. Three positions
Floating where the hand moves freely over the strings but less accurate as no reference point.
Posted where finger four rests on sound board for greater accuracy but movement is
restricted.
Gliding Finger. Pinky on the soundboard but it can move around but does not lose contact with
the sound board.
Strumming
Two angles to think about. First the up and down from the elbow as the pivot point across the
strings. I prefer up and down and with no arc for a consistent tone (an arc occurs from the
natural movement from the elbow and tends toward the bridge at the end of the down
stroke).
The second angle is any movement away from the up and down strum such as turning the
pick away form the guitar towards the end of the strum. In other words any arc away from the
face of the guitar. I try to keep the pick nice and level
With Strumming the action also comes from a loose wrist. A stiff elbow only approach just
feels too rigid.