I’d suggest using 3 collections. Of course your naming convention can be different than my example.
- Categories (contains two items Personal and Commissioned with flexibility to add later on)
- Tags (contains People, Places, and so on)
Fields: Name, Category(single-reference), Tags(multi-reference)
This will make it easy and flexible for the client. They upload an image into the Photos Collection, give it a name, assign 1 category, and any number of tags.
As the designer, you can now add a collection list to any page and use filters to show specific items. For instance, and pageX only show items from Category=Personal and Tag=Place. Linking to the collection template page for Place would show all photos tagged with Place no matter the category.
This will give you tons of flexibility to control which photos show up and where. The client will only ever need to use the Photo collection to upload new work because they can even create new categories or tags from the new Photo item form.
If the client also wants to be able to organize a group of photos as a Project or Work then create a 4th collection. Add the new collection as a reference field in the Photos collection.
Here are some helpful links. Hope this helps. Happy designing!