Yep. Most of my projects end up with at least one sheet of paper like this. I write counts of blocks and patches. I scribble my math as I go. I sketch really crude drawings of blocks or corner arrangements. Sometimes I use graph paper to draw layouts, and when I do, the margins of those sheets are covered like this, too.
The calculator is an essential part of my tool kit, too. The quilt math IS NOT HARD! There are a small number of formulas. If you know where to find the formula (and YES there are several I look up every time) it is easy to plug in the numbers. No more long division like we did in grade school. Only the most basic algebra. You don’t have to solve geometry proofs or integrate the area under a curve.
Most of you know I use EQ7 regularly, too. Like a lot of electronic tools, one of the main benefits is ability to re-do your work quickly. Adjust a shape or block here, change a color there. You can do ALL THAT and more with paper and pencil (and colored pencils or crayons or markers.) You can just do it more quickly with the software.
Other design tools are several of the books I own. The books I like best are those with historical quilts for inspiration, and those with design principles, strategies and techniques, rather than patterns. Occasionally I troll Google images for ideas but not often. No Pinterest or Instagram, either. I’d rather spend my time doing than looking.
My favorite tool is my brain. What a wondrous thing brains are! 🙂
What design tools do you use? Let us know in comments.