Simple, lush, gorgeous. This sun-lover attracts bees and beneficial insects, resists deer, takes salty seacoast wind, and looks great with any number of plants. All it asks in return is good drainage and full sun.
I love it with just about any ornamental grass, pink or yellow roses (it attracts the beneficial bugs that eat aphids, which makes them a great companion plant to roses!), Heathers, Hardy Cranesbills, and anything with purple foliage.
I trim individual stems back partway early in the growing season if size needs to be reduced, or remove stems selectively towards the end of the season once trimming stems partway no longer looks graceful. Nepetas get cut back completely in winter once they’ve died down.
You can divide them every few years to control size, but it doesn’t seem necessary for the plants’ health – I’ve never seen them die out in the center as many undivided perennials do.