I'm not a Lightroom user (often), so I'm not overly familiar with what's available natively, but you might find a plug-in like Topaz Adjust 5 to be just about the right size and shape of ticket. It works from within both Lightroom and Photoshop (and any PS plug-in compatible editor, as well as a standalone with a free lightweight host), and offers both global and local adjustments. The ability to paint effects in and out is, I think, a deliberate nod to the environments that won't allow you to play with layers in the host program.
(No affiliation—I'm even deliberately avoiding the affiliate program—just a very satisfied user.)