There’s a lot of space above the shelf in most closets. Even though it’s a little hard to reach, it’s a great place to store seldom-used items. Make use of this wasted space by adding a second shelf above the existing one. Buy enough closet shelving material to match the length of the existing shelf plus enough for two end supports and middle supports over each bracket. Twelve-inch-wide shelving is available in various lengths and finishes at home centers and lumberyards.
When the top is done, we want the edged MDF and the oak countertop to have exactly the same dimensions, and for their width to exactly match the width of the base.I could see three ways of doing this: 1, join the MDF to the countertop and use my belt sander to sand down their joined edges to match the base; 2, join the MDF to the countertop and use a hand plane to plane down their joined edges to match the base; or 3, use a flush-trim bit against a straight edge to route the MDF to the width of the base, then join the MDF to the countertop and use the flush-trim bit to route the countertop to match the MDF.
In ancient times, the woodworker’s bench consisted of a plank or split log with four splayed legs. Descendants of those benches are manufactured today, usually with a top of hardwood slabs glued together. The norm nowadays is four straight legs supporting the bulk above, often with braces and a shelf below. Despite the improvements, the linkage to Greek and Roman antecedents is still evident.
My first attempt at making a cutting guide didn't work. What I ended up with worked fine for cutting panels, but the guide-strip was too narrow, and when the saw was extended fully for rough-cutting the 4x4's the clamp heads got in the way. So I made another. Actually, I made two more, so that I could cut one into shorter pieces that would be easier to handle.

Grizzly is a company currently undergoing an upheaval. This brand was once known as a manufacturer of professional grade tools and equipment for woodworking products. Though, in recent years, that reputation has begun to slip a bit since being bought by the Chinese company SIEG. These days, whether the Grizzly product stands up to its previous standards of excellence often has more to do with what you are buying than the company itself.