First off, to all the Gun Guys (and Gals)... thank you. You are in a very real sense the most important ambassadors of gun ownership in the world. You put a normal, everyday, and (one hopes) friendly and respectable face on something that is popularly demonized and unfamiliar. That's important.
I grew up in southern California. SoCal is a place where nobody admits to owning a gun and where, when a new gun store opened, people in the area literally protested in front of the store. A very "anti" place.
You know what? There are a lot of gun owners there. A lot of alone, silent, and disenfranchised gun owners who hide because everyone hides. They are a secret repressed minority without even a symbol to identify each other. They can't even scratch fishes on the ground.
My signature line, "Don't hide arms, get sidearms!", was chosen in part because of that. I think the collective silence of most gun owners is very dangerous. We stand silent and seeminly alone, often outright lying about our gun ownership, while surrounded by others who own and enjoy firearms. We own them, they own them, but nobody talks. They won't talk about it because nobody does, we won't talk about it because nobody does, and the very fact that something is taboo (not to be spoken of) tends to lend menace and attract abusers.
I did that, hid my interests, for years. I enjoyed talking to my parents about them but if we were in public we would literally talk in code, as though we were talking car engines and never using "scary" words. It was ignition (lock/hammer/primer), cylinder (barrel/chamber), fuel (powder), pistons (bullets), and so on down the line. I didn't talk to friends about gun ownership. I wasn't the ambassador. The perceived costs were too high... professional damage from being the gun nut guy, social damage for the same reason, added security risks of people targeting you to steal guns, etc... all of it added up to a price I didn't think I was willing to pay.
Then I started thinking about the real cost of silence. The real costs. Short term costs like not being able to go shooting with friends and coworkers. Long term costs like allowing more and more restrictions to gun ownership.
I started talking to people. I took some friends shooting. I talked to coworkers. My ultra-left (I refuse to call them liberal...I'm a liberal...I believe in liberty, freedom... they want restrictions) friends gave responses like, "You own guns? You are as far from violent or a nut as anyone I can think of, why do you have a gun?" Yes, that's an actual quote. Some coworkers didn't care, others were anti, others wanted to go shooting.
Moving to Texas from SoCal has been an education for a lot of people. They assume, me being one of those California types, I must be anti. I enjoy disabusing people of that myth. I recently had a coworker (who has been in Texas for 10+ years) come to me asking about concealed carry courses. I gave him the card of an instructor and had two other coworkers (who both have CHLs) talk to him about why he should take the course. I've had others ask me about Texas gun laws (specifically the new car carry law). It is funny but gratifying that I, a Texas resident for a year now, am bringing Texas natives up to date on their own laws. I'm no shotgunner but I've got an open invitation to two coworkers who have never fired a shotgun at all to go shotgunning whenever they have some free time. It's fun. There are other upsides. I've had a chance to buy guns I never would've known about if I'd kept quiet.
Still, it's a balance. I still don't like visibly carrying a firearm to/from my home. I don't want to be a target, I don't want to get into trouble at work. Nobody does. Sometimes, though, you've just got to take the risks. The cost of silence is just too high.
I can't really help on the "how to bust myths" front. I generally don't try to educate about that sort of thing. I'll just laugh and say "only in the movies" but I won't really try to convince people that physics is physics. Physics is physics, people learn those laws eventually. At this point I'm more interested in breaking the silence and getting them shooting.