There are 3 ways to hold a guitar : the usual method, the classical method and standing up.
Please note: the description below is for right-handed guitarists! For left-handers who want to play left-handed, then everything below should be reversed : left = right, and right = left!
The usual method of holding a guitar is sitting with both thighs horizontal, and preferably leaning slightly backwards. Why can’t a chair be too high when you play the guitar? In the normal playing method, we put the body of the guitar on the right leg. When a chair is too high and your thigh tilts diagonally forward, you quickly notice that the guitar can easily go down and sometimes smack against the ground.
It is advisable to use either an office chair where the height can be adjusted, or a regular chair with a riser under the right foot (there are special footstools for this, but a book or the like with a few cm height is a cheaper alternative). Then place the guitar on the right leg, and hold the guitar close to your body.
The right arm hangs the guitar and can rest on the body so that you get a good hold and the guitar cannot fall. Optionally, a guitar strap can be used to keep the guitar stable and also to be extra sure that the guitar is secure. For children we always recommend this to be sure that the guitar would not hit the ground. Hold the guitar neck with the left arm. Take a relaxed position and last but not least: straight back!
The second method is the classical method, which can be applied to a classical, electric and acoustic guitar. Preferably you use a footstool from the music store or another riser for this. Place the left foot on the footstool, and place the guitar on the left leg. Lean the right arm over the guitar to hold it in place, and hold the guitar neck with the left hand. The difference here is mainly that the guitar neck protrudes more to the left and that the guitar neck is kept straighter than with a normal posture on the right leg. The advantage is that the frets are more easily accessible along the entire length of the guitar neck. To play lower on the neck like open chords, this method is less useful.
This method is sometimes also used on electric guitar, but mainly with soloists who want to get to the high frets more easily. But for electric guitar I don’t recommend this : an electric guitarist who is going to perform usually plays standing up. And the posture of the guitar standing up leans closer to the ordinary method. If you play according to the classic method and then play standing up, you get a very uncomfortable feeling.
The third method is to stand upright with the guitar. If you ever plan to perform in front of an audience, it is advisable to practice standing up in addition to the classical or ordinary method. You will soon notice that playing the guitar standing up feels completely different from playing guitar while seated. Of course, a guitar strap is needed to play standing up, which is attached to the fasteners (buttons) on the guitar, left and right on the guitar body, or to 1 attachment on the outside of the guitar and at the top of the headstock. There is a lot of difference between guitar straps. It is important that the belt is firmly attached to the guitar buttons (fasteners) so that the belt cannot unload. We at Guitar Studio use Schaller Strap Locks that do not come off like the traditional fasteners.
There are luxurious leather guitar straps of more than 100 euros on the market, but we ourselves use guitar straps of barely 7 euros and they are rock solid! How long the guitar strap should be, each one must determine for himself. When the guitar hangs higher, it is easier to play. When the guitar hangs lower, the guitar neck is more difficult to reach … But it looks so cooler! So : it’s up to you! Anyway, try for yourself what plays most comfortably. It also depends on the size of the body of the guitar: for example, an acoustic guitar will not have the same length of guitar strap as an electric guitar. So it’s best to buy a separate carrying strap for each guitar.