Okay, flat picking style guitar playing usually refers to playing melody with a flat pick usually on an acoustic guitar. And you might've heard some guys like Doc Watson, Clarence White playing fiddle tunes using a flat pick and a down-up down-up motion. So that's been a really influential style for guitar players in all different shades of country music from super traditional old time bluegrass to electrified rock and contemporary country.
So it really starts with just playing a basic melody and getting your down-up down-up strokes organized so that you're picking down on a downbeat and you're picking up on an upbeat. There's going to be exceptions to that rule, but that's generally the rule that you're going by. So let's take for instance a traditional melody that you might hear from a fiddle flat picked on the guitar.
So that's sort of what a fiddle might play filtered through the guitar and the flat pick. And, you might play a melody that's more known as a vocal melody, something like. And that's how you flat pick a guitar.