At this time of year the trades are moving into the north, and you will have a hard slog to windward until you reach Martinique. I strongly encourage you to sail in the lee of all the islands. From Trinidad until Martinique you will be hard on the wind and the west-setting current is quite strong (ask advice of the Trini sailors for course adjustment for current from Trinidad to Grenada - I don't have Carib. charts here and don't remember anymore. You will welcome the protection that the islands offer you as you make your way north. I've heard experienced sailors, having crossed the Atlantic to the Caribbean, complain bitterly about the wind and seas as they left the lee of Grenada. You might want to leave one or two reefs in the main until you reach Martinique.
The pass between St. Vincent and St. Lucia (St. Vincent Passage, or St. Lucia Passage - don't remember) can be nasty as the wind speeds up between the mountains of these islands. I recommend that you tack in very close to St. Vincent, then as you poke your nose into the passage ease the sheets a bit and be prepared for very strong gusts and seas until you get into the lee of St. Lucia. Now that I've said it, of course it will be a "piece of cake" - it only knocks you on your beam ends when you're not expecting it!
Once you are on the approach to Martinique you'll be able to ease the sheets onto a reach, and it's really lovely sailing from then on to St. Thomas. Because the weather can sometimes be nasty, I suggest that you work very hard the first few days to be sure you have enough time. We found that leaks and breakages occurred on that 3-4 island hard slog, and we welcomed the lee of St. Lucia and Martinique to rest and clean up the mess.
Fair winds, and a sense of humor if they aren't there.