Hold a chalk line from the farthest stud on one side of the wall to the farthest stud on the opposite side of the wall. If the chalk line touches the surface of all the studs, their alignment is even and no measures to assure the drywall's evenness are necessary. If the chalk line touches only a couple of studs and completely misses others, then installing drywall shims will help to even the studs.
Staple drywall shims directly over each wall stud that recesses. Attach a drywall shim, staple it every 12 inches to the stud and then add additional shims, one at a time, if necessary.
Check the studs' evenness again with the chalk line. When all of the studs touch the line, you’ve added enough shims to start hanging drywall.
Hang the uppermost drywall wall panels first, positioning them horizontally and butting them tightly together. Insert drywall screws 6 to 8 inches apart on the edges of the panels and every 8 to 10 inches apart in the center of the panels. Every screw must hit a wall stud.
Apply a 1/4-inch bead of drywall glue to the studs where the edges of drywall panels will meet. The glue acts as a gentle shim to hold the panels out slightly from the studs.
Apply a 1/2-inch bead of drywall glue on studs that will be beneath the center of each drywall panel that recedes.
Position a drywall panel on the wall, and insert drywall screws along the edge studs at least 16 inches apart. Insert two drywall screws over each stud in the center of the panel. Use the same procedure for each drywall panel.