An approach which has worked best for many is to find a couple of recipes which appeal to one's taste rather than buying a single vendors flavorings at (more or less) random.
Once you have chosen recipes, but flavors from one of the better vendors which has multiple brands and is known to combine fair prices with good service and quick shipping.
Bull City Vapor is excellent as is
ecigexpress. Wizard Labs meets the first two criteria but is slow to ship. There are others but this will give you a good start.
Picking out a good recipe
before buying will avoid the newbie post, "What can I make with these flavors?"