From 390 cut east at Wayland across to Branchport on Keuka Lake. There is a nice run down the western side of the lake to Hammondsport. Dine at the Village Inn, food and Beer are great. You can then take the back roads to Watkins Glen or Corning or cut down to Bath and re-join 390/86 to Corning.
I can also recommend the “Marmalade Cat” B&B in Watkins Glen as a place to stay.