Now that I have a supply of wide slabs to work with, I decided to play with them for bed #2. The corner posts are salvaged barn timbers, and the head/foot boards are thick pine slabs cut with the chainsaw mill, about 20" wide. I left them with a 'live' edge on top to keep it rustic looking.
I put them together with structural screws, but pegged the holes to give it the timber-framed look. This was much easier and looks the same.