Below is what I carry almost all the time, Pico in a sillicone sleeve, short rda with a slip ring to seal the air supply in my pocket. It's as inconspiuous as it needs to be for stealth. After that it's minimizing visible vapor, looking for discrete moments, and slight of hand. Generally if there is little or no visible vapor people don't react.
It goes all day on work days. For all day outings I've got a Pico Mega which is rarely needed.
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