Holding a plectrum, is a matter of taste. However, a few pointers to bear in mind is to not have a tight grip; keep it loose, but not so loose it moves every time you strum. Let your other three finger move freely when strumming and even use them to steady your hand if you’re picking strings, by resting the tip of your little finger on the body of the guitar.

Holding a plectrum / pick correctly

Bottom line to holding the plectrum is:

• Maintain a loose and relaxed wrist
• Don’t hold the pick so tight, you’re knuckles turn white; keep the grip relaxed
• Keep the pointy part of the pick at right angles to your thumb
• Practise, practise and practise

Here’s a video, showing a master guitarist holding the plectrum in the aforementioned manner to flatpick, enjoy