I tend to carry more ecig stuff and spares than I think I'll need on any given outing. After trying MANY different types and sizes of cases, I have opted for several small, inexpensive soft-sided camera cases with multiple compartments (for multiple batteries, juice bottles, tanks and any other accessories I think I'll want to carry). One is in a nice camo pattern. Another is a more formal basic black. They all have an optional shoulder strap for convenient hanging off my car seat, on a hook by the door, or for carrying on long treks on foot.
Beats a fanny pack or a full man-purse, keeps my hands free, and gives me that fashionable, man-about-town, or, tourist-toting-a-small-camera look (hehehh).
These have turned out to be for me the most versatile and convenient ecig luggage available.