There’s nothing more aggravating than guitar string buzz makes noises it shouldn’t. An issue that comes up often is subject of guitar string buzz. It’s a problem that happens often to players. What is it?
String buzz is caused when a string strikes against the top of a fret.  It creates a buzzing sound. There are a few reasons why this occurs from the strings on your guitar:
1. Are you playing the note in the right place?
Watch your technique. See if you’re fretting notes at the right spot behind the fret. If your fingers are too far behind your frets then you’ll hear some unwanted buzzing.
2. Are you striking your strings too hard? 
Don’t be rough but be firm with your instrument. If you hit the strings too hard when strumming, it can cause the strings to vibrate up and down too much (as opposed to side to side), increasing the chance of string buzz.

Apply proper finger pressure

3. Do you apply the proper amount of pressure to the string when fretting your notes?
Make good contact with the frets with the tips of your fingers. Again-this is a technique issue. Are you playing sloppily or clean?  Finger strength is important. Are you having trouble playing barre chords?  Strengthen your fingers. How? Play more and practice details such as clearly articulating each and every note. Maintain good string contact with the top of each fret.
4. Are the guitar strings too light for your technique?
Look at any new changes in your guitar strings. Have you changed the gauge? If so, this will cause a different tension when tuned up and therefore cause you to have to change your attack. If you cannot adjust then string buzz will occur.

New guitar not set up yet

5. Is your guitar new? Has it been properly set-up? Does it have the gauge of string that you normally use? Is the action too low?
With low action comes a trade-off. Super-low action can cause a sring buzz. However, if you can live with it-it is so much easier to play. Not all buzz will translate through an amplifier. So, if slight buzzing occurs when un-amplified, ignore it when plugged in, because you’ll never hear it anyway.
6. Is your guitar is set up properly?
Taking it to a guitar tech can help a lot. Get it set up right.

Uneven frets or humped neck

7. Can the buzzing is caused by uneven frets, an over-bowed or humped neck?
A good guitar tech can tell. He’ll level the frets, straighten the neck and get it right for you.
8. Are the tuner bushings loose?
If so you’ll clearly hear a good amount of buzzing and rattles that can be hard to pinpoint. Check and see if they are tight.
9. Does the string buzz occur when the note is played on and open string?
This will occur when a string “nut” slot is cut incorrectly. It can be fixed by a competent luthier or guitar tech. It sounds much like a “Sitar” effect when the open note is played.