At a high level, I took a mirror I had bought cheaply at Target and attached vinyl lettering I designed and made at TechShop San Jose.
Total cost: ~$12
Mirror: $10 (I think)
Black Vinyl from TechShop: $2
Step 1: Design the Checklist
I then used Adobe Illustrator to flesh out the size of the stickers (just a little under half the width of the mirror was what I wanted), to pick out the font I wanted, to design the squares (I used Wingdings and added an outline to thicken the boxes), and to arrange the list visually.
Below is how the design looked digitally:
Step 2: Use the vinyl cutter
-Check the weave settings when you're sending to the cutter. I have cut my lettering before because I set these up wrong
-Triple check the length and sharpness of the cutting blade. The right length makes all the difference after the design cuts.
-Have enough material where if you mess up (likely), you'll still be able to work.
-Give yourself lots of time to remove the vinyl not a part of the design.