Measure the length of where your wall will be. Next, measure the height. For purposes of this article we will assume you have a length of 5 feet and a height of 8 feet.
Saw two 2-inch-by-4-inch boards to a length of 5 feet.
Saw two 2-inch-by-4-inch boards to a height of 7 feet 9 inches. For the height you must deduct the width of the top and bottom stud. Assuming the width of the 2-inch-by-4-inch boards is 1 1/2 inches, deduct 3 inches from the overall height and cut the height of the stud to that measurement.
Saw an additional two 2-inch-by-4-inch boards to the height of 7 feet 9 inches. You will need one stud for every 16 inches of wall. Take the length of the wall in inches (in this case, 60), and divide by 16 to give you the number of studs needed along the wall. Round up to the nearest whole number. For the 5-foot wall, divide 60 by 16 and your result is 3.75 studs, or 4 rounded up. The two studs you cut earlier are a part of this calculation.
Place the 2-inch-by-4-inch boards you have just cut on the floor. Looking down at it, arrange the studs as follows: Place the 5-foot stud horizontally, standing on the width side Place a 7-foot-9-inch stud on its width side on each end, vertically, matching up with the end of the 5-foot stud. Place the other 5-foot stud on top of the two 7-foot-9-inch studs, horizontally. You should now have an empty box.
Hammer two 8d common nails on the ends of each stud to hold the frame together .
Measure 16 inches on center for the two remaining studs and nail two 8d common nails in each end to secure to the frame.
Use your stud finder to find the ceiling stud, if your garage ceiling is covered in drywall. If there is no stud where you want your wall, then you must nail up a crossbar. Access the other side of the drywall (if applicable) and measure the distance from one beam to the other. For this article we will assume 14 1/2 inches. Cut a 2-inch-by-4-inch board to 14 1/2 inches and nail two 8d common nails into each end. Nail up four of these crossbars, evenly spaced all the way across where you will attach your wall.
Lift the wall frame up to stand it up to the ceiling. Nail the frame to the ceiling crossover studs using two 8d common nails for each crossover stud.
Drill with your masonry bit through the wood and into your garage concrete floor for the anchors. Drill a hole every 2 feet.
Hammer in the anchor and tighten down the nut by turning clockwise until tight with your pliers.
Install a door in between the partition sides by framing the door into the wall in between the studs. Cut the bottom stud out to the width of the rough opening of your door. Next, cut two studs to the rough opening height of the door. Measure from one of the wall studs to the other where your door will be. Cut a stud to the length you just measured. Place the two studs for height in the entryway and nail to the bottom stud. Place the stud you cut for length on top of the two studs to make an opening for your door. Place a nail in each stud through the top stud to secure the frame. Nail each side of the top stud for your door into the wall studs. Install the door by sliding into the opening and securing to the studs with screws, based on installation instructions that came with your door.
Hang your drywall, leaving 1/2 inch space at the bottom, and screw in. Use your drywall screws and screw in every 16 inches, vertically on the drywall, from ceiling to floor. Continue hanging drywall until one side is completely covered. Repeat with the other side.
Mud the joints of the drywall. Place a layer of joint compound on the seams with your putty knife and place your drywall tape over this, centered on the seam. Place another layer of joint compound over the tape and smooth out. Let dry 12 hours and then place another layer of joint compound, smoothing it out and allowing it to dry. Continue the layering process until the tape is covered in joint compound and feathered out to smoothly match the drywall until you do not see that there is a seam. You are now done, and you can proceed to your desired texturing and paint.