Step 1. Changing Your Strings
To see if you need to change your strings, run a finger underneath the string and feel for dirt, rust or flat spots. If you find any of these, you should change your strings.
Always make sure to stretch your strings properly. After you have installed a new set and have them tuned to pitch, hold the strings at the first fret and hook your fingers under each string (one at a time) and tug lightly, moving your hand from the bridge to the neck. Re-tune and repeat several times.