I'm a fan of the big Cartos. I'm not a fan of being stuck with one juice. The ones I use hold 3+mls. Expense neccessitates creativity. That said, I've recently become fond of layering. Basically, I'll go around the cart with one layer of flavor, then another, continuing until filled. I use 2 flavors of e-liquid that seem like they would go well together. My current joy is Vanilla Ice Cream and Cinnamon Roll. I've found that this way, I can keep the boredom factor to a minimum, as well as helping the old thin pocketbook with a bit of variety. 