Attach the Drywall
Use a drywall saw to cut outlet markings outside the lines on drywall (Image 1).
Secure the drywall to the studs (Image 2). Countersink the screws, making sure to only dimple the paper. Be careful not to break through the paper or this will compromise the structural integrity of the drywall.
Make reference lines on the drywall (Image 3) as a stud reference when screwing in the drywall.
For windows, cover the window and come back to cut it out after the drywall is secure (Image 4).