Sitting and holding the guitar correctly is the foundation for establishing good practice habits. Good practice habits equal good playing habits!
We are all, including our guitars, different shapes and sizes. Adjustments should be made accordingly, however, the fundamentals stay the same.
Holding or grabbing a chord in the right way is often met with frustration. Sensitive fingertips, strength, and dexterity are all factors. Once again, we all, including our guitars, are different shapes and sizes. Adjustments will be made on an idividual basis.