All other instrumentalists learn early on to play with 100% control does not come naturally. For one reason or another alot of guitar players don’t develop great technique. Many hours of study and practice are necessary, and you can practice to your heart’s content but if your posture and hand positions are awkward it’s going to work against you, and take longer.
Like my favorite uncle used to say “Practice doesn’t make perfect, perfect practice makes perfect”. It is important to be comfortable when you are playing. And learning how to sit, how to finger a chord or note properly, how to pick accurately can go a long way in developing some skill.
Some guitarists are natural and develop their own technique; however this doesn’t work for everyone. Here are some loose guidelines that will help get you on the right track.
Don’t be holding the guitar up, that is the strap’s job. If you are sitting then it is the job of your knee. You want your hands to be free to fret and strum. Try and have your strap adjusted to the same height. Learning to play guitar in a consistent position will help alot.
Alot of guitar teachers will tell you the guitar has to be in an exact certain position, I don’t completely agree with this maxim as everyone is different. Bodies come in different shapes and sizes and so do guitars. So experiment, and observe your body and position when you are playing. Pay attention to your arms and hands especially, but keep in mind your whole body plays a role.
In most situations your thumb should be invisible to anyone standing in from of you. Check in a mirror if you are unsure if this is the case. Yes, some of the best guitar players in the world (Hendrix is one example) have used their thumbs to great success, but you should probably leave advanced techniques like these until later in your development.
Generally keep your thumb in hitchhiking position, pointed away from you with the ball of the thumb in the center of the neck. Your thumb will more than likely move around when you play, especially if you are fretting awkwardly shaped guitar chords. But for the most part try to keep it in this center position.