If you're using a JOYE 510, I'd recommend Cignot.com
Don't throw your old cartridges away--you'll use them in the future to refill with that
juice--factory filled cartridges cost too much.
Myself, I would make contact with a bunch of those suppliers--get sample bottles of what you think you will like. Take into account that over a period of about two hours the flavor you are
vaping seems to loose its' taste--you getting use to it. When that happens change to a cartridge with a different flavor.
Welcome aboard!