I’m not an expert here, I’ve been a few places and read a lot and I’m certain there are many differing opinions on this topic.
Generally speaking, if you want an easy experience because land is always in sight, help can get to you fast, the depths are generally deep, but not too deep, there are mooring balls everywhere so anchoring isn’t a problem, food/supplies are generally in the bay you are in, you are sailing fairly protected from bigger waves due to islands and reefs, then the BVI is a good place for you. It’s almost as if the boat is an RV, and you are just driving around a large (beautiful) campground picking a new spot every night. In my opinion, it’s a great starting spot for someone new to bareboat chartering.
After a couple of times of doing that you might want to see a little more of the Caribbean. You might not want the crowds (IE: all the mooring balls will fill in the bay you are in by 5pm — sometimes 3pm). Again, I am no expert on the Caribbean, but the next most logical place for me was to sail the Grenadines because of the many islands, mountains, volcanoes, and because it’s not as overrun as the BVI.
Now, where do I sail to/from? Some factors might come into play here. How much wind is there and from what direction and where are the swells coming from? There is a great website to look at these forecasts called Windfinder. Generally speaking for December, you desire to go South from St Vincent because the swells are from the ENE. This is why (in part) for this trip, we chose to go one way from St Vincent to Grenada.
Other factors might be places you want to see or snorkel. You will have to do that research yourself and be informed on what is available to you. The Tobago cays is a draw for me. I thought it was going to be about snorkeling there, but recent reports say a hurricane did some damage and the coral isn’t doing so well. Since I’m a photographer, the beauty of this location is worth a stop. Reading other people’s trip reports will also inform you on interesting places to stop and certainly reading Chris Doyle’s Guides will help you. Also – You can find a few itineraries from people who have done this trip before, just google for your ‘location and itinerary’.