In the same way that we create Contact groups for Companies or Individuals, using Categories, we can filter, sort, and save our lists used to make Maps of our various sales territories. When we do this, it is easy to pull up those entries later, review and add to as necessary.
Filtering Maps
When you filter the list, the map automatically filters to the matching area. I typically switch over to Grid layout and filter from there, since I find the spreadsheet-style filtering more intuitive (by right-clicking on a column header); but you can actually filter from any screen, using the "..." (3-dots) button in the upper-right... The views are all linked (including Charts), so when you filter in one, the others also filter to match.
Saved Filters
The last filter for each view that each User makes is saved; and Sales Reps when they login would typically only see their own assigned territories anyways, so they kind of take care of themselves. If you would like to see a territory at a time, you would just filter on the Sales Rep column to get their specific list of Customers.
Geographic Filtering
Another nice filtering options is either City, or even partial-Zip Code (to get a metro area, for example). For the Zip Code example, you would filter on the Business Address column, using the "contains" filtering option. For example, contains "787" will get me all of greater Austin, while contains "7874" will get me the lower and west-suburbs.
The kind of filtering you do will mostly depend on customer-density, so it is going to vary from one rep and geography to another. Let me know if there is a specific combo / area you are trying to achieve, and I can probably be more specific with the filters.
Categories are Groups / Keywords
Use Categories to save groups of customers after you do some filtering. Here are the steps as they are now:
Go to Companies, filter by City and/or State, Sales Rep, Company Type, etc.
Click the "Select All" button in the top-left column header of Grid view (checks all the entries you are currently showing).
Use the Batch Edit button to assign a new Category, such as "map: Greater Boston".
Repeat for as many variations as you like. In the future, filter on the Categories column (using contains again) to pull up everyone in a particular group.
I am not sure how much you use Categories now, but the usage of it is as a generic / keyword grouping mechanism for both Companies and Individuals. Here are some that we use, just so you get an idea:
Newsletter: Users
Newsletter: General Audience
Industry: Jan/San
Industry: Automotive
Member: AIM/R
Member: PTRA
We actually have probably 100s of these checkboxes, so that we can easily pull up groups (and combinations of groups) for our various sales efforts. More information on Categories in general, can be found here: https://www.mrsware.com/apps/search?q=categories
You can see all of the Categories you have been using in Web, under the Contacts menu -> Contact Categories. If you haven't been tracking keywords, it does take some setting-up to get running. Buying Groups, Industry segments, even Job Title are all things that you can track, and may be able to import lists of those or use Batch Edit to add multiple contacts to a group all at the same time.
Request for Feedback
We are also planning to do some more features around mapping, so any input you have would be great.