Drywall can transform your space very easily, but first you need to make sure the framing is ready for drywall.
A good carpenter will know how to adjust your existing framing and add new framing to prepare for drywall. Something as simple as a bowed stud can ruin an entire drywall project.
Before your drywall installer comes to do drywall, check that your framing is straight, level, and plumb. Check inside and outside corners with a square, and make sure there is sufficient backing in the corners to accept drywall.