OK, so I've never been to the area. Besides riding Highlands Scenic Hwy and visiting the Jefferson Baths I have no plans. Any must visit lunch stops in the area? Any Sat. afternoon bluegrass venues nearby?
I don't how scenic the Highlands Scenic Highway is. There is at least one nice overlook. Not sure it's worth doing even once given the other options in the area. The ride from the hotel to the start of it is HUGE fun though (on 219) and continuing north (down the mountain) is big fun too.
The General Store in Paint Bank on 311 is worthy. The loop Smoker posted will get you there.
To the north on 219, Hellbender Burrito in Davis has lots of fans (right near Blackwater Falls State Park if you want something to see). The Purple Fiddle in Thomas has eclectic acoustic music on weekends, but I think that is evenings only.
A visit to The Hutte restaurant in historic (but tiny) Helvetia is always nice. Take 219 north and make a left on some county roads. Follow to Helvetia. Continue out to route 20 and take that south to Webster Springs, then 15 over to 219 and back south for a nice loop.
The Cass Train Museum (66) and Greenback Radio Observatory (28) make a couple nice tourist stops with worthy riding in between and you can make a nice loop out of them.
The Seneca Rocks Discovery Center is a nice visit and lunch at "The Front Porch" in downtown Seneca Rocks is nice on a nice day, watching the climbers across the way.
It's pretty much sport-touring heaven in that part of the world. Great riding in every direction. Stuff to see if you're into that and some interesting eateries along the way.
For scenic overlooks, the Germany Valley overlook on 33 (between Seneca and Franklin) is a favorite. The Confederate Breastworks overlook on 250 is nice. There is a nice one on 39 just to the east of 220. The overlook at the WV/VA state line is pretty awesome, as is that section of 33. The VA side is epic IMO.
This a nice loop that includes Cass Railroad, Greenbank Observatory, and Helvetia with lots of nice riding along the way (211 miles):
https://goo.gl/maps/dDMgtH7GQgoYou can add an hour of awesome riding by taking 250 east to Monterey (then double back) if you want. So good it's worth doing twice.