For the HTML5 version of mapgen2 I added an “icon” feature that adds a hand-drawn icon at the center of each polygon.
This is an easy-to-implement technique that can make the maps look hand drawn. Since the polygons are already spaced evenly but not on a grid, we can reuse the polygon locations for these icons, and it looks like they’re scattered about.
I drew these icons on an iPad using the Concepts app[1] and exported them to SVG. (see exported SVG). Feel free to use these icons in your own projects, 
[2]
under the Creative Commons Attribution 4.0 International License[3].
I was inspired by StarRaven’s Sketchy Cartography Brushes[4], which were designed for use as Photoshop brushes for people drawing maps by hand. StarRaven also has another set[5] available. I drew my own because I wanted icons that matched the biomes I was using. The biome colors are: