Constructing the Frame

• 1). Measure your child's mattress. These measurements, plus a half-inch on each side, will dictate the size of the platform bed frame you're going to build.
  
  
• 2). Based on these measurements, cut the pieces for a rectangular frame out of 3/8-inch-thick plywood. You can cut the plywood yourself or get it cut at a hardware store. You'll need two shorter pieces for the top and bottom ends, two longer pieces for the left and right sides, and one large rectangular piece for the top, where the mattress will rest. You'll also need two 2-inch-wide pieces that are an inch shorter than your left- and right-side pieces. These are rails for the top piece to rest on.
  
  
• 3). Decide the height of your platform bed frame based on how high you want the bed to be off the ground. If you're making a bed for a toddler, keep it fairly low in case the child rolls out.
  
  
• 4). Mark 2 inches down on the inside and the outside of your side frame pieces. Using these marks, screw your 2-inch-wide wooden rails to the inside of the side frame pieces. Use five screws for each rail. Space them out evenly.
  
  
• 5). Screw the frame together. Use three screws on each side.
  
  
• 6). Put your top plywood piece on top of your rails. You can see that it's slightly inset, which will let the mattress fit snugly into the frame. Attach it to the rails with two screws on each side.
  
  

Upholstering the Frame

• 1). Fold over the cotton batting so that it is a double thickness. Now cut strips of it to fit around your frame's sides. Make sure you leave room to overlap it at the top and bottom of the frame, so you can fold it over the top and bottom.
  
  
• 2). Fold the batting over the top and bottom of the frame. Pull it so it's snug against the frame, and staple it down.
  
  
• 3). Cut strips of fabric that are the same size as your strips of batting were. Starting on the bottom of the frame, fold the fabric over the edge of the frame and staple it over the batting. When you reach the end of a strip, fold its end over so the raw edge is hidden, and put the next strip's raw edge under this finished strip. Pull the two strips taut over the frame, and staple them over the batting. When you're finished with the bottom of the frame, turn the bed over. Fold the fabric over the top edge of the frame and staple it over the batting. Remember to treat the raw ends of each strip in the same way you did on the bottom.
  
  
• 4). At the corners, fold the fabric so it lies flat, and staple it so it's tight.
  
  
• 5). Put the mattress on top of your upholstered frame. Add some sheets, blankets and pillows, and invite your child to check out his new bed.