Don’t do “art” (where the maps are involved that is), just draw simple maps to know that the land of X is there and the land Z is east of the land of X with the city of P 20 miles from the border.

You don’t need more than that for writing your book, the map is just for reference purpose since the reader won’t see it. If it’s an hindrance don’t do it. But quick and easy sounds like the operative words as long as they help. 🙂

Remember that R. E. Howard’s Hyborian world was designed out of a map as simple as that one: https://upload.wikimedia.org/wikipedia/en/5/5c/Maphyboria.jpg (and even this one is edited the original one was even simpler actually 😛 )