If you go to Google Flights, you can enter a departure airport (JFK or BOS, but don't forget LGA, HPN, SWF and BDL) and some dates, and click "Explore". It will show you prices for a bunch of different trips to different destinations. You can then move the map around, zoom in to different areas, etc. This is great for getting a general idea of where you could go and what it would cost. The nice thing is that because it shows you the flight costs, you can rule out expensive destinations (well, at least expensive-to-get-there destinations) and zero in on the ones that are within budget.
I once used this "fishing" method to select Honduras as a vacation destination. I never would have considered Honduras if Google Flights hadn't shown me this option, but after it showed me that the flight was quite inexpensive, I did more research to figure out what we could see and do there. It turned out to be a great vacation, with part of our stay next to a beautiful national park and the other part on a small private island with just a few other guests - all of it very affordable.