Stretching:
A step in the string changing process that most people skip or don't even realize exists is the step where you try to relieve in stored energy within the strings. Most people strap the strings on and go... and they experience a few days where their strings will stay in tune for about 5 minutes then slowly go flat... This is because the strings are stretching... To help the strings break themselves in I always get the strings in tune... Then I slide my finger underneath the string and pull straight up (away from the body of the guitar) and wiggle it around.... When it's pulled away from the guitar I then move it from side to side (parallel to the guitar).... I do that to each strings a few times... after I do all six strings I will retune and do it again... Until the strings start to stay in tune while you're stretching them... Then you know the stored energy within the strings molecular structure has been released. Some people don't like to do this because They like choose to work teh strings in naturally... However, when you have to change a set of strings and play a live set in an hour... you'll wish you had. You'll be retuning after each song.
I do it everytime I change strings. It also helps the strings to sit in my bridge saddles... Sometime when you install a set of strings a string may not be seated properly on the bridge... and as you tighten the string it will create a pinch point often times affecting the tone and in some cases causes buzzes and premature string breakage. Stretching the strings works the string around in the bridge saddles so the string can find the proper place to sit. It also may correct any issues that the string ends may have in their position in the bridge as well... Sometime the string ends may sit at an angle and shift with a certain type of movement that causes tuning instability... Stretching ensures that the string is seated properly as well.
