How do you best utilize textual inversions?

Seems like they're best for landscapes, but I could be using them wrong?

It depends whether it's a "Style" textual inversion, or a "Subject". If you take a look at the ones I've published, they're "Styles" - they lead your images towards a particular theme - Autumn, or Winter - so yes, good for landscapes.

But they can also be used to capture the likeness of a particular person/subject. Here's an example of a real person (with consent), being translated into a cartoon-style character, via Textual Inversion. This allows us to have consistent characters/faces between images.