Recently I had picked up some old wood from an individual on Craigslist and found several pieces that I thought would work (below picture), fir, cedar, and pine.
Each piece had to be planed and sanded as they were in pretty rough shape.
The design was really pretty simple:
The 4x6's were used as the posts. Onto each post I then attached a 2x2 to which the 1x's were attached for the back and main part of the headboard and footboard. After the horizontal boards were attached to the 2x's I trimmed out around the edges with 1x2's and then finished off the top of head and footboard with a 1x6.
There was quite a bit of finish sanding to do and then I finished it with several clear coats of satin poly with sanding in between each coat.
The bed rails were simply made with 2x6's that were lap jointed and then connected with lags. Overall it ended up looking pretty good and is nice and solid.
Finished product: