jellybean,
without knowing where you are staying, or what time of the year, I will give you some general advise .
First off, traveling solo is the best. And Negril, being a small village makes traveling solo a lot easier than other destinations.
You just need to learn the ropes, and the game.

As others mentioned, the men will hound you....
Lots of solo women come to Negril to see the men Lots!!! So the men will assume you are there for them as well.
If you are interested, get your groove on , but if not, be stern but respectful about it.
If you enjoy walking the beach, know that you will be approached not only by higglers trying to sell you there wares but by all men.

They will ask you, where you are from, where are you staying, how long, do you have a man....etc....

Your best bet is to get to know the staff at whatever resort you are staying at, they will be a wealth of knowledge and answer most questions you have.

Leave your Louis Vuitton and any fancy jewels at home,
Do not walk the beach or anywhere alone at night......................and have a blast !!!!