Here are some folding sawhorses that I built a few months back and added them as a project. I had recorded the building process but was unable to get the files off of my camera to edit them due to a lost software, but I bought a new software so here is the video!
You can find some more information like the cutting layout, dimensions, hardware and some more detailed photos on my blog, The Woodworking Trip.
I really like these sawhorses and I have built myself two sets. One that I use at work doing construction that sees the jobsite very frequently and is put through pretty demanding work. They have help up great for quite some time without showing any signs of giving up.