Design Tool Box
All the goodies I keep in my little book-box on my desk
Here's the basic Xacto knife for all your detailed, paper cutting needs.
It's silly, I know, to actually buy these faked out boxes posing as books. I like that it makes my space look more like a somewhere I want to think and work on ideas, rather than an Office Max catalog. I use the big book to as a monitor stand and a place to store completed sketchbooks and the mid-size book as my toolbox. Plus they're $5 or something at Ross. Find a container that you want to see on your desk every day!
This is the least sexy tape of them all. It's great for quickly taping mocks up on a white or foam-core board and later taking it down. You can rip it with your hands and it just seems to never run out. Unlike scotch tape, it won't rip apart the fibers of the paper when you need to get back to sketching. I also love using this kind of tape when wizard-of-oz paper prototyping.
The ruler I have and love is 12-inches, clear with a metal edge. The metal edge is key for cutting paper and tracing lines (it also keeps ink off your paper). This one is a close comparison but has 90s style Marker-Felt font and dark lines. It's clear, has a metal edge and is on Amazon Prime. It's not sexy but it gets the job done.
The double-tip hexagonal Muji pen was a happy accident. The grip has a soft touch and the shape means it never rolls off the table. It's double sided so you can get a thick and thin tip which is great for wireframe sketches. The ink is a bit softer and won't bleed through paper like sharpies.
If you are in or have friends in Japan, hunt down the Nanuk sketchbooks. The page is a soft cream color, with thread binding and absolutely no branding or logos anywhere. Unlike most sketchbooks (even those from Muji) these are nice and tall which is ideal for note taking and designing for web and mobile apps.