I used to make these pixel perfect wireframes dokuments with this Blokk font, specific color schemes, special wireframes-images and what-not. Nowadays I just draw grey boxes and use Helvetica. I just use enough details to get the idea across. On my last project I only used pen and paper. I've saved so much time it's silly when I compare. And I can use all that time iterating the idea. 10/10 Would recommend.