When holding the plectrum, also known as the pick, place the plectrum between the thumb and the index finger. Do not use three fingers [thumb, first and second] and hold it like a pencil, just use two fingers.
If I take the plectrum away you will see that the thumb comes down on top of the side of the fingernail of the index finger. The plectrum is inserted in between with a small amount of the plectrum sticking out.
I can then lay that against the guitar strings and have a nice even hit.[David demonstrates]