I recently built two outdoor tables based on a bait table you would find at the end of a dock. I started this project over a year ago when I left all of the 1x4s out in the weather. All of the boards weathered slightly differently and there was a nice variety of colors and warping. A year later, I used them to create the table surface. All of the boards are pressure-treated.
I wanted it to look aged and as vintage as possible so I intentionally made each board slightly longer or shorter than needed by fudging the pencil marks when i was measuring. After randomly placing the different colored boards I used a random-orbit sander to knock off all of the edges and corners. I did this as randomly as possible to make it look naturally worn and not like i used a router.
When I was finished, I took a saw blade and rolled it all over the surface to makes dents and small holes in addition to the claw side of a hammer to rough up the surface.
I'm pretty happy with how they both came out and I'll probably use one of them as an extra work-surface when brewing.
Table dimensions are 60"w x 30"d x 30"h. Both tables are pretty identical so I only took picts of one: