See 18:38 for a demonstration. I also clamped the board to the side.
Nota bene: because I wasn't convinced I'd be able to make boxes neatly enough to the measurements on my first project, I installed the drawer slides in the cabinet before constructing the boxes. That gave me the relative width I needed since the box needs to straddle the slides.
I should also note that because this was my first project (literally the first things I cut besides the test cuts at the little introduction to woodworking course I took at the maker shop to get familiar with the table saw around someone who knows what they're doing), it took me a couple months to build the courage to start, and each step required rewatching videos to capture things they gloss over, like how to clamp things or hold the nail gun to avoid blowout, etc. I tried to meticulously plan out every step before I went to the garage. And then not get angry with myself when, for example, I notched 4 extra drawer faces for the slides (seen on the rightmost bank)
Also had a homemade pizza tonight. My wife does a magical sourdough crust and we had one that sat in the fridge extra long. We were just cleaning out the fridge with the toppings tonight, so some Italian sausage, onions, and kalamata olives, and the end of some romano and Parmesan with the last of the puttanesca sauce.
Definitely recommending your toppings combo for the next round! Did you drizzle the honey before or after the oven?