I always carry a note book with me. It has my plan for the day (https://medium.com/@kristiandupont/high-resolution-planning-...), random notes and random doodles. I got into it after purchasing an old copy of Thinking With A Pencil (https://www.amazon.com/Thinking-Pencil-Henning-Nelms/dp/1626...) which I think was a recommendation from some thread in here.

I am not sure what it does for me, but I've been quite consistent for well over a year now and I do find all my old note books are quite fun to scan through.

Another fun type of graph paper is composed of triangles in a hexagonal grid, commonly used for making isometric drawings:

http://web.mit.edu/16.810/www/Isometric%20Drawing.pdf

For those of you looking to improve your by-hand visual communication skills, a cool old book is _Thinking with a Pencil_ . I picked up a copy a few months ago, and have been enjoying working through the exercises as I find time (which also includes isometric techniques):

http://www.amazon.com/Thinking-Pencil-Henning-Nelms/dp/08981...

Thinking with a Pencil, by Henning Nelms, would be a better choice for practical drawing and design, rather than Drawing on the Right Side of the Brain.

http://www.amazon.com/Thinking-Pencil-Henning-Nelms/dp/08981...