Pick direction is extremely important and, most of the time, a beginner's problems can be traced to incorrect or unsure pick direction. Experienced guitarists can control pick direction and use unconventional techniques, but beginners are highly urged to stick with the tried and true "down-up" alternating pick direction. With this method, all downbeats are played with downstrokes and all upbeats are played with upstrokes. If strings are crossed (cross picking), pick direction continues as stated and you may very well have to jump over a string in order to pick it with an upstroke. It might seem more efficient to use a downstroke when crossing strings, and indeed some players do this, but it is the exception rather than the rule. Alternating down and up strokes give the music a natural pulse and beat. Using consecutive down or up strokes will produce a syncopated, off-beat feel which may be desired or not. In any case, consecutive down or up strokes is a technique for experienced players who can use it to change the flow of the music.

Cross-picking is a technique of jumping, or "crossing", strings. Strictly speaking, it follows a certain pattern, using either a "forward" or "backwards" roll with a certain number of notes per phrase. Generally speaking, cross-picking can be any phrase in which strings are skipped or in which a roll or some sort or another is played. The "floating" technique, for instance, is a variation on cross-picking in which open strings are deliberately played against fretted notes for a piano-istic sound. Cross-picking is based on Carter-style playing in which a bass melody note is surrounded by strums; in cross-picking the strum is replaced with a picked note or notes. George Shuffler, who played with the Stanley Brothers for many years is the main guru of strict cross-picking, while most modern guitarists, especially those from the Tony Rice school of playing incorporate a looser cross-picking style. Norman Blake is another master of cross-picking, using a style somewhere between Rice and Shuffler. In any case, cross-picking usually derives the "main" note from the melody and the cross-picked notes from the chord.

Pick direction is an important topic among cross-picking aficionados. Shuffler uses a Down-Down-Up-Down (DDUD) direction which places a strong emphasis on the off-beat notes (2 and 4). Others prefer to maintain a more normal Down-Up-Down-Up (DUDU) direction with its resulting accents. A very small number of guitarist have good enough pick direction to vary direction freely, sometimes playing in complex patterns like DDDU/UDDD. These guitarists often are not playing direction as much as they are playing accents, and frequently are not even aware of pick direction. Again, beginners and intermediates are advised to stick with one technique until they have it mastered.

I personally think that DUDU pick direction is like learning solos from tab: you need to do it at first, so that you'll have a firm foundation in good technique, but as soon as you've got it mastered, play whatever is natural. Ideally, after you've been playing for awhile, your ear will tell you whether you need a down-stroke or an up-stroke, regardless of where the note lies on the beat. But don't rush into it; 10 years doing strict DUDU isn't too long for most people.