Draw out the design for your vanity. It will comprise of a desk-like table, a chair, and a mirror. Any additional personalizations can be drawn in, and you can adjust the basic structure.
Start marking out cuts for the desk portion. If it's for a little girl, be sure the measurements are a little smaller to accommodate for that in comparison to a full grown adult. We will do examples based on a full grown adult vanity. The top should be 17 inches wide by 42 inches long. This can be cut out of MDF or plywood.
Cut the side panels on the table saw. They will be two boxes that will have doors for storage and support the top desk part. The sides will be 32 inches long by 16 inches wide (four total of these). The back will be 32 inches long by 12 inches wide. (there will be 2 of these). The bottom will be 12 inches by 16 inches (there will be two of these).
Create the base for the boxes. It will be made out of a 2x4 piece of wood. Cut four pieces 16 inches long and four pieces 12 inches long. Cut all the corners at a 45 degree angle on the table saw. Match two of the 16" pieces with two of the 12" pieces to make a rectangle. Place wood glue on the cut angles and use the clamps to hold the rectangle together for it to set and dry. Once dry, use nails to go through each corner for additional support.
Take the pieces cut for the boxes and for the back corners, and then cut them at a 45 degree angle on the table saw. Place wood glue on these cut angle and set with clamps to allow it to dry. Then place nails through the corner several inches away from each other down the side.
Place wood glue around the edges of the bottom of the boxes and then place on top of the base piece. Nail through the bottom piece to the side pieces of the box to secure it in place. Apply wood glue on the base made for the boxes and place the completed box on top and clamp. Nail diagonally from inside of the bottom box base piece into the 2x4 base piece.
Cut a frame for the box to place the door onto. It will be cut from a 1x2 piece of board with four pieces 12 inches long and four pieces 32 inches long. Cut the corners at a 45 degree angle. Place wood glue on the angles and clamp them together to set and allow to dry.
Line the frame up to the box and nail it every couple of inches into the box piece.
Cut the door pieces 10 inches wide by 30 inches long. Screw on the hinges onto the door pieces and then onto the frame piece of the box. A decorative molding can be added to the doors if wanted.
Cut a trim piece for the top. Cut it out of 1x2 board two 17 inches long and two 42 inches long. Cut the ends at a 45 degree angle. Then, glue them to the top piece and nail them for additional support.
Place the top onto the boxes made. Place glue on the edging of the top of the boxes and then line up and set the top piece on it. Use the clamps to secure it to allow it to dry. Nail the top piece in from the bottom through the box pieces.
Take a premade mirror or build a frame and place a mirror in the frame. Attach the mirror to the desk with brackets or hang it on the wall above the vanity desk.
Sand down the vanity with the sander. Wipe off any additional dust. At the bottom of the base, baseboard molding can be applied for a decorative look if wanted. Cut it to size and nail in place.
Apply the paint or wood stain using the paint brush with long brush strokes. Allow the first coat to dry and then apply a second coat.
Pick out a stool or chair to go with your vanitie's design. Add decorations to have the two match.
Add organizing baskets and shelves in the storage boxes of the vanity to help with organizing and storing materials.