Assess your available space. Though there are a number of stage construction options available to you, from the traditional proscenium style to the centralized "arena" model, you will largely be limited by the amount of square feet you have to work with. First, designate your longest wall, and place the stage in the center to fit in the largest number of seats for audience capacity.
Decide how big you want your stage to be. While envisioning, keep in mind any space hogs you will be using on stage such as monitors, microphone stands, stage scenery and other necessary props. You will want to have your stage large enough so that performers will not feel claustrophobic while retaining a healthy seating capacity.
Create a to-scale blueprint of your stage with the help of a ruler. To ensure stability, you will need to section off your stage into smaller parts for separate construction. Decide whether you want the typical rectangular stage as your model or choose from a thrust or "fashion runway" style. Next, divide your blueprint into 6-by-6-foot pieces, and pencil in the intervals on your drawing. For example, if your stage is a 12-by-18-foot rectangle, you will need to make six 6-by-6-foot platforms.
Cut "feet" out of your 2-by-4-inch at the desired stage height. For low ceilings, you may want to stick with a foot-and-a-half stage height, whereas a 3- to 4-foot height is possible in higher ceilings. Cut four lengths for each platform at your desired stage height.
Construct the frames for your platforms. With the remaining 2-by-4-inch, cut four 6-by-6-foot lengths for each platform you require. Cut each end of these at a 45-degree angle with your mitre-box or table saw to ensure that all four 6-by-6-foot lengths connect in a perfect square, and drill the ends together using at least three 1¾-inch screws for each joint. Next, cut a 5-foot 8-inch length of 2-by-4-inch for each platform you are using, and screw each one at both ends in the center of each square for support.
Cut your plywood into 6-by-6-foot sheets with the table saw and screw each sheet to each 6-by-6-foot frame of 2-by-4-inch. For this, you will want to screw 3-inch screws all along the border of the platform, adding another screw every foot-and-a-half (don't forget to screw the plywood to the middle plank as well). Next, turn the platform over and screw each of the four legs along the ends of each corner using at least three 1¾-inch screws for each leg.
Temporarily attach your platforms together in the placement you desire for your stage with a C-clamp. Make adjustments until you are satisfied with the location and begin to screw the platforms together, using at least four 3-inch screws for each combined side. Remove the C-clamps, and test your structure.
Paint and decorate your stage as you desire. The most common method is to paint the stage black or a matching color to the floor or walls. Select a facing of either fabric or plywood for the front of your stage and get creative.