I found this frame design online, thanks to Ana White and Big Box Detox at www.ana-white.com:
Isn't it beautiful? So pretty and inspiring. I already had my recycled headboard, but I used the plans to build the rest of the bed frame, with a few modifications.
I used 2"x 6" pine to make the rectangle. The size is for a California king mattress, which is 72" x 85". It is 4 inches narrower, and 5 inches longer, than a king size bed--this comes in very handy for tall people (like my 6'3" husband!) I planned on having the box spring rest inside the frame for extra support and height, and having the mattress rest on top of the box springs. The dimensions of the frame are 74" wide by 88" long, to give a little extra room for the box spring, batting and fabric that I'd add later.I checked that the corners were square by measuring diagonally from corner to corner, and connected the pieces together with 3 screws at each corner, with 3" Spax brand screws.
(Scroll to the bottom of the post for a link to Spax screws on Amazon.)
After making the rectangle, it was time to put triangular braces into the 4 corners. I used two 2" x 4" x 5" squares, cut in half. I screwed the triangles into the 4 corners, using two 2" Spax screws on each side (four per triangular brace), screwing from the outside of the frame in. They are about 2" down from the top of the frame, so the box spring can rest down in the frame a bit.
On top of the supports, I screwed down a 2"x 4"x 88"of lumber. On a narrower bed like a twin or full, this extra support wouldn't be necessary.
...and cut up an old brown curtain that I was glad I had saved, into 4 strips. I used masking tape to help me cut it straight.
Tada! Chunky, solid wood bed frame. For about the same price in lumber as an ugly metal frame! I think I spent about $75-$100 total. Let me know what you think, or if you've tried this project!