It would help to know what guitar you are playing. Some guitars lend themselves to using the upper frets more than others. For instance, my fender strat gives easy access to the upper frets with its long scale length and cutaway design of the body. In contrast, even though my gibson les paul has a cutaway in the body, the way the neck is attached to the body and the smaller scale length compared to the strat make the upper frets less accessable.

Acoustic guitars differ in design for access to the upper frets - some have a cutaway in the body.