Whether this is for books, or comics, or even TTRPG, you can design some top quality maps with out any artistic skills.  All you need is a photo editor that has the ability to render a cloud layer, and “stroke” an item.  It’s really not as weird as it sounds.  Photoshop and GIMP are the level of software you’re looking for.  Paint.NET or ProCreate won’t work.  I’m using Photoshop, so your menus may not look exactly like mine.

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