Here is my advice on tuning the guitar strings (tuner or manual)
To my surprise, even the experienced seem to have gotten this wrong.
We haven’t approached the obvious like how to utilize an automatic tuner, or how to tune manually based on audio reference (you find applications in common cellphones). Let’s talk here instead of the most important and practical, the string to be tuned first.
In my experience as a guitarist, rules on tuning the guitar do not take into account the size of the strings. A common mistake is to begin with the thinnest string first, such as the low E, then moving on to the thicker strings. This is a mistake.
Tuning a thin string does not greatly affect the tension of the thicker ones, but adjusting the tension of a thick string affects the tension of the thin strings. By tuning a thin string first, the pitch is degraded when you move on to the larger strings, forcing you to repeat the process.
So let’s refer to the most common case of a not completely out of tune guitar, such as when you take it out of the case and get ready to play.
Turn on your automatic tuner and tune the low E at the first. Then move on to the other strings, from largest to smallest. The last will be the high “e”. A quick second check and you’re ready to play.
If the strings are not new it will not be necessary to stretching them, vice versa you will have to proceed to stretching all the strings, double-checking the tuning of the individual strings several times.
Happy Playing ?