Maps, of course, communicate an incredible amount of information. But sometimes this can be a liability—each part of the map drawing as much attention as any other. Often you want the map reader to focus their attention to a specific area of the map; the rest of the map can remain for context, but just have a more subdued appearance.
Here is one way to do this in ArcGIS Pro.
There are many flavors of this trick that you can use to get just the sort of hey-look-over-here sort of effect you need. The most important thing is to consider what, and where, the map’s job is and design it in a way so that its audience will look right where they ought without effort. Plus it looks pretty cool, and that counts for a lot!
Happy spotlighting! John