Honeymoon is a period of a lifetime and that makes it absolutely necessary to make it good enough to have a lasting memory of it.
It is utmost necessary that both husband and wife decide the area to be visited. While deciding this few things should be taken care off. The first being the weather of the area you are deciding to visit. Choosing Kashmir in December, January or Kerala or Goa in May, June will be catastrophic. You might end up confined in the hotel room with no chance of visiting the places. Also going to a hill station like Shimla in June will mean over crowded places. So it has to be a very careful choice.
Once the area is finalized then you have option to either visit a travel agent or take it upon yourself to make the itinerary. I talked to few travel agents and found out that they are quite expensive. Overall you can save about 15 to 20% of your overall budget if you decide to forgo the services of a travel agent. In my case I found Google very helpful. I was able to find hotels, tourist spots and other tit bits about each city I was planning to visit. I and my wife short listed 5 hotels in each subsequent city that we were to visit. I just booked the ticket and hotel for the first city. After that with the list of hotels of the next city, I would ask the Travel desk of the current hotel to do a booking in the next one. Believe me it is surprisingly easy this way rather than going to a city and finding a good hotel. The reason of me not going for advance booking for all the cities was that the cities I was visiting were new to me. I did not knew which city would appeal me better and where I might have to stay longer just because of the tourist spots there. The travel desk also is the best to advise on the mode of travel to the next city and again are more than ready to help you in getting the tickets booked.
So your problem is limited only to finalizing the location and trust me an open itinerary is much more fun and adventure than a tightly schedule and planned one.
So happy honeymoon