Incompetech has a good solution. Just be sure to ignore any downloads or ads other than the "Download PDF" button on each page - I accidentally clicked on one of the ads and it triggered a malware alert on my AV. The PDFs themselves check out just fine against various AV scans.
Each one of these can be customized for grid size, line color, weight, etc. Great for drawing.
The most useful templates for me:
Nested Square Grid
Cornell Graph Notes
For hexes, I find a 0.1 inch size gives me what I want for scale. For lines on small grid pieces like that, 0.1 point lines were ideal , with light grey as the color. Using black as the line color was my first impulse - but when I printed the page out, I realized my folly, as it was too dark to draw on!