How far in advance is the ideal time to book a vacation. Heading to either Dominican Republic or Jamaica next summer (from DFW)... book now or wait until...when?

Flights are what usually get you. I sometimes see flight price drops when southwest brings out their new pricing for places they fly to. But resort wise, the earlier the better usually and they are usually refundable so it doesn't hurt to book in advance and can cancel if you find a better deal, etc.

The last couple of trips I've taken, the cost of the hotel/resort dropped and I had to cancel an existing reservation and rebook. I just have to check periodically in the months leading up to the trip to make sure I'm getting the best deal. I usually book about 6 months in advance when we are traveling to a popular summer destination (like Hawaii).