1. Try to travel on weekdays instead of weekends, as flights tend to be cheaper on Tuesdays and Wednesdays.
2. Book your flights at least three weeks before your travel date to save money.
3. Use travel search engines like Kayak, Skyscanner, or Google Flights to compare prices from different airlines. Don't forget to check the airline's website directly, as they sometimes offer exclusive discounts.
4. Set up price alerts or sign up for email notifications from airlines to get notified when prices drop.
5. Avoid traveling during peak travel times such as holidays, school breaks, and weekends as prices tend to be higher.
6. Consider flying into Fort Lauderdale (FLL) instead of Miami, as flights may be cheaper. You can then take a shuttle or rent a car to get to Miami.
7. If you have a travel rewards credit card, consider using your points or miles to book your flight and save money.

By following above tips, you may be able to find a cheaper flight from New York (JFK) to Miami (MIA) and save money on your trip.