I know "cliff notes" implies something brief, but I'm afraid it's more complicated than that. Not so much the mechanics of the configuration, but the fact it's fully configurable and there are so many different data and personal preferences it can be adapted to. It's clear we need a comprehensive wiki entry for this, but I don't have time for anything like that right now. I can offer a few general tips...
While not essential, it helps a lot to have a well
organized library and a thorough understanding of how to configure
view schemes in Standard View. With that background, the easiest introduction to Theatre View is to
Add...Library item from Standard View (at
Options - Theatre View - Items to Show). I recommend the item to add be a
Panes and Details view you are already familiar with. These views explicitly include
Categories (panes) and
File Info (details)—the two principal components of the Theatre View configuration. You can then readily identify aspects of the view that may need to be handled differently in Theatre View.
Unfortunately, a view added in this manner cannot be modified in the Theatre View configuration. But with a clear vision of what is wanted, it's not difficult to configure the view from scratch. First,
Set rules for file display to define what items are to appear in the view. That might be as general as
[Media Type]=[Audio], or something more specific (e.g., for separate views for popular and classical music). Then specify the categories you want to use to narrow the selection of items. This can be omitted (so the view will always be a list of all items) or as complex as you like. In most situations, just a few will suffice (e.g., Genre, Artist, Album for music).
Next, the fun part. Having configured how to get there, use
Customize file info panel (under
Theatre View - Appearance) to specify the layout of the File Information list and details views (referred to as "small view" and "large view" in the configuration). This is done using any number of fully customizable templates, each of which includes a search to specify which files it is to apply to. The default configuration includes the templates that are obviously necessary—one for each media type. But this can be used any way you like. You might decide, for example, you don't want separate views for popular and classical music, but will use separate templates so different information can be displayed for each type—in the same view. Each template allows any field to be placed in any position and displayed in small view, large view or both. But that's not all. Expressions can be used to combine and reformat fields, or just to customize the field label.
In typical MC fashion, the possibilities are endless and mind-boggling. This is why I suggest having a clear understanding of Standard View and your own library is important. But don't be put off by that idea. It's also quite possible to dive in, work through the configuration step-by-step and get it what you want by trial and error. After doing a few views that way, how everything fits together will become clear. And for some of us, that's the best way to figure out what we really want. I find I tinker with my configuration, and then use it for a while to see if the changes actually work. I'm not bothered at all my configuration includes views I seldom use—because I've created others that work better.