If you are just doing cartomizers (KR808
batteries), I suggest picking up the Strong Sample Pack from Smokeless Image. It has three different menthol/mint flavors in it. An icy one called Ice Menthol, a smoother menthol with a nice easy taste, called Menthol Burst, and a Mint. That pack will also have Cappuccino and a Classic Grape.
Liquids are good if filling blank carts. I like something called Winter Vanilla from ECBlendflavors.com. It's a combination of wintergreen and vanilla. Add extra flavor and a cool hit, and you will have a wonderful tasting liquid that delivers a very good hit. I marathon vape it with 0mg nic.