POSTURE

Posture is also very important. Correct posture will help your overall performance. You need to sit up straight and make sure you have a flat back. You may find a tendency to want lean over the front of your guitar so that you can see what you're doing with your fingerings. Instead of looking over your guitar, use your fret dots to know where your fingers are. Ultimately you want to play without looking at your instrument and fingers.
A lot of novice guitar players will sit anywhere; place the guitar on their right thigh and play. You may wonder why this is a problem. Well, when your posture is completely out of alignment, this will result in sloppy wrist, hand, and finger habits. Also, correct chord formations and scale constructs won't be possible up the entire neck of the guitar.

You’ll want to get yourself a chair that fits your height. When you are getting a chair make sure that when you sit in it, your feet are flat on the ground. You also want to make sure that your lap and knees make a 90 degree angle. Any deviation on this will result in incorrect posture. If your chair is too low, your arm, wrist, and finger movements will be limited. If your chair is too high, the tendency will be to lean over your guitar and the result is incorrect posture. A good measure is to stand next to the chair and it should come up to your knees.

Second, you want to get yourself a foot stool. You will use the foot stool to elevate your left leg. The guitar will rest on your elevated left thigh. I caution at getting a foot stool that is too high. While the foot stool allows for the most secure and correct body posture, it can cause some stress to your lower back.

Third, be sure that you sit at the edge of the chair. Do not slouch. Sit up straight. It's okay to look at the guitar and your hand, but it isn't okay to lean over and look at them. Relax your shoulders and keep them square to your torso. Do not let yourself lean to any side. There are a couple of exceptions to this when you are playing up in the twelfth frets and above.

Once you have finished in those frets, resume posture. Now I'm sure you have the right foot phenomenon. What to do with the right foot? I tuck it under the chair and rest on the ball of my foot. Some like to have it almost completely extended to where it's almost on the heel. You decide what works best for you.