Saw Horse Supports [Rockler] - brackets that slip over the saw horses and hold another 2×4 or two for supporting the middle of the table. A four-pack of steel brackets runs around $13.
How To Build The Best Saw Horses
Doesn't get any easier than this! I'm making a set for use outside from PT lumber and I can just leave 'em out there! Efficient use of lumber as well. jayscustomcreations.com saw horses
How to make a saw horse
Sawhorses are an essential construction tool, and this article highlights 5 of the best—3 DIY designs, with complete plans, and two off-the-shelf favorites.
Adjustable saw horses! And they look pretty slim, so easier to store!
Adjustable-Height Folding Sawhorses using standard door hinges.
Working Alone | Popular Woodworking Magazine