I often use hexagonal grids when conceptualizing games in my sketchbook. Here are a few different sizes of helpers that can be used as quick stencils. They might also be suitable for creating battlemaps, I guess.
The grids have a 5 x 5 arrangement (23 tiles) with either 20 mm tip to tip (20 x 17.37) per tile, flat to flat (23.09 x 20), 1 inch tip to tip (25.4 x 22) or flat to flat (25.4 x 29.33). Every size comes with spacings of 0.8 / 1.2 / 1.6 mm.
Should there be a greater demand for other configurations, I could possibly deliver them later.
Though, if you should need very specific arrangements, sizes or spacing, maybe OpenScad or an online hexfield generator are better solutions.
Update: I added 3 inverted versions. They use the same grid with 1 inch flat to flat but different line widths: 1.6 mm for fine liners and other thin pens, 2 mm for pencils and 2.4 for ballpoint pens.
The author marked this model as their own original creation.