Tools
This workshop uses QGIS to generate reference maps for publication. QGIS isn’t the only way to make a reference map. However, it provides ample detail and involves your original work. For a comprehensive list of different mapping tools and software, see here. QGIS is quite beginner friendly, especially if you want to just make a simple reference map. And, if you do decide to do more complex spatial analysis, you’re halfway there.
If you’re interested in spending more time honing the aesthetics of your map, you can always export a rudimentary map from QGIs and conduct advanced editing in a graphics illustration software such as Adobe Illustrator or its open-source alternative, Inkscape.