Using the sides as a template we mark the edges
and positions of the holes for pre-drilling.
Now it’s important this goes straight down, not that way or that way. It’s important to do this with mdf sheet to ensure the chipboard screws don’t split the material. And when you’re finished all your guide holes on the top and the bottom you gotta change to the 3 mm bit.
We choose a 3 mm drill bit to drill the end grave so the screws will be secure and a tight fit.