I started making some rough cuts with my 3/4″ MDF and ended up realizing I had miscalculated a few measurements. This is why it’s good to dry fit stuff! Plus things are not always square and perfect. I used clamps to get a basic idea of what I was doing and get the exact measurements. I ended up changing a couple. I’m not an expert…I was in awe of the carpenters who can just take measurements and then go back to their shop and create the entire thing which fits perfectly.