I used a 5/8 inch board and attached it with pocket holes. The screws act as clamps while the glue dries.
You can see the difference between the standard pocket hole block (3/8 inch holes) and the micro block with (19/64 or 7mm holes). The micro jig is one of those tools that I only use a few times a year but I have found it to be worth having on hand. Kreg makes pan head screws to be used with this micro jig. I use the micro jig when working with 5/8 and 1/2 materials.
While I was working on this last project I was drilling holes in 3/4 inch material. This set up is my third generation K-2000 pocket hole jig. The K 2000 was the latest jig on the market when I started to work for KREG Company.
Even though there are several newer models of jig I have kept the K 2000 set up. Having a dedicated 3/4 inch set up is quick and time efficient. You can see that the K 2000 has no built in chip collection which came one generation later. If I am working on a project with many, many holes to drill I use the K-4 model with the chip collection.