Comfortable shoes are a must: for sightseeing, for climbing hills on the winery tours, for standing at the bar while tasting wines
Toiletries and Medical Supplies: Sun glasses during the summer because there is definitely a glare off the lake and the clear air in the hills will dry you eyes out on a windy day.
Photo Equipment: We went through 24 pictures in 4 hours.... so bring enough film or preloaded cameras.
We never did find a local store that sold those shoot-and-mail cameras
Miscellaneous: Casual clothes are appropriate for everywhere we went in the area. This is a blue-collar town.
Don't dress too much like a tourist here. They'll probably recognize you if you're from town, and if you're not, they'll know, but they don't need obvious reminders. Dress casual here!
Photo Equipment: This is a beautiful area... wineries in the sunset light... old barns... lots of film, as usual.
Camping/Beach/Outdoor Gear: Bring some stuff to play with in Keuka!