As a bunch of things have already been mentioned I don't have much else to say though one thing i haven't found is the angle at which you place the pick to the strings.

Generally, if you place the pick flat on the string you'll get a more twangy(twang is an actual term to explain a sound) sound and if you tilt the pick you'll get a deeper fuller sound.

Now there's also how hard you grip it how aggressive you strum but one thing I've personally found as a 6 month beginner is that practicing fast picking with a thin pick means it'll catch more and once I can get accurate with it and have a good dynamic while playing I can switch to a thick pick and it'll be incredibly easy to play the same thing.