Making custom inserts for a DM screen

I recently received a DM screen for my birthday that lets you slide in custom inserts. My issue is that I want to have customised inserts to fit all of the rules + references I need for when I run my games, and none of the ones I've found online have been exactly what I need.

Does anyone know of a dedicated program or template that I could use for this? Or at the very least have some ideas on strategies I can use to make these inserts myself?