Not at all discreet myself either, and I vape with a 6ml DCT hooked up to a eGo battery, not exactly the setup for the sore eyes. I vape it in the middle of classes, one of them, I sit dead center in the middle of the classroom. Low resistance, HUGE vapor clouds. I've had two ladies ask me what it was and I just taught them what it was and they said that it was a damned cool setup and told me to continue.
Vape while walking through Wal-Mart had 3 employees, all females lol yell at me saying no smoking in here. What did I do? I said in a smartass attitude, "I'm not smoking, it's a personal vaporizer, water and nicotine is all that i'm breathing." Their response as I walked past them 5 mins later after grabbing my little 750ml of cheap wal-mart vodka for cleaning, "Hey, let me try that?" My response? "Nope, get your own, they're pretty cheap

."
Don't be discreet about vaping, don't go into smoking areas while vaping. Vape in areas that are considered non-smoking areas at all costs. People will call you out on it and that's when you swallow your pride and start schooling. It's the only way people will learn. I've had from the curious to the raging, each and every single one of them came out with powerful knowledge and a great support for vaping.
My next tactic? Although not true by any means, is tell these people that I was a PAD smoker since I was 14 and the day I started to vape, I dropped the cancer sticks and never looked back. My mottois, It isn't who or what your past and current deal is, it's how you portray yourself to everyone that will make the biggest impact.