Proper Slide Guitar Technique
Slide guitar is physically easy in one sense — just drag a slide over the strings, and you can instantly hear the effect, right? However, proper slide guitar technique is not quite that simple. It can be difficult to control the sliding and keep the buzzing and rattling artifacts to a minimum.
Slide an object like a glass or metal tube over a left-hand finger.
Slides are usually worn on the third or fourth finger.
Rest the slide on the strings (not pressed down), directly over the fret wire.
Resting the slide on the strings and playing over the fret (instead of behind it as you do when fretting) takes a little finesse, but eventually, your intonation and tone will improve.
Change pitch by gliding the slide along the string.
This process produces a smooth, continuous change in pitch (sometimes called portamento).
At first, your slide playing may sound clangy as you move the slide around. You can improve your sound by using one of two techniques:
Dampening (or muting), which involves placing your unused left-hand fingers lightly on the strings behind the slide (toward the nut)
Employing right-hand palm mutes
Slide guitar doesn’t require left-hand strength the way normal acoustic guitar playing does, but it does require finesse! Focus on intonation first, rhythm second, and dampening third.