The old adage "Write what you know" has some truth to it, but some people take it far too literally. If people only wrote about what they knew at the time there would be no science fiction, no fantasy, no speculation toward the future, no dreaming ... all that would be left would be dry first-person experiences.

I prefer to take the phrase a little differently: Write what you Know. Know, as in Truth, as in the greater Truths that bind us all together. Such a definition doesn't rely on knowledge of particular details. It's more an awareness of the human condition and universal laws than whether you actually know what it feels like to be shot. 

However, when you do write (or talk, or film, etc.) about something, you also have a duty to try to portray it accurately. Again, I don't mean this term literally. Don't punish people with your research and include every tiny step on how to build your own thatch hut unless you are actually documenting how to do this so other people can replicate the process (in which case, go for it, cover every teeny tiny step!) I'm also not a fan of such detailed accuracy that you make it easy for someone to perpetrate a nasty crime.

Instead, the goal is typically to portray the flavor and reality of the thing without letting the nitty gritty details overwhelm. I tend to want someone who's a genuine practitioner not to roll their eyes at the ignorant stupidity of what I've put out there, and at the same time don't want to completely lose someone who doesn't really care about every step in making a snow cave since what they're there for is the emotional experience of it. Add the usual caveats for adjusting for your audience, the genre, the goals of the piece, etc.

So how do you manage capturing the essence of something that you don't know how to do? Or what if you're just writing something more straightforward like a journalist piece where you need to make sure you understand how something works, or have someone to quote with some facts? You start by tracking down the elusive beast known as a source.

Many people find it very difficult to approach strangers for assistance, especially strangers who have knowledge that they may admire. Let me start by saying that for a variety of reasons, a source is as afraid of you as you are of them. For one thing, there is the unfortunate fact that if the source is well-known enough or their field is covered enough, they may have experienced or heard horror stories of other journalists misquoting, slanting, or just plain garbling what they had to say in a way that may have reflected poorly on the source themselves. 

You can't do anything about past problems they may have run into or heard about. What you can do is conduct yourself in a manner that is respectful and clueful, showing them that you understand their frustration and that you will do a far better job on their behalf. If you're writing/filming/etc fiction then you might offer to show them a draft and give feedback. A journalist may not have that luxury since often you don't want to show people the article before it goes out, or you may have influence/pressure placed on you to alter it to be more favorable to them, which is not the goal either. Recording the interview is one method of protecting both them and yourself in this regard. Interviewing through email if you're working in a written medium is another, as you can just copy and paste the text.

But before you interview a source you have to find them and get them to agree to talk to you. I tend to think of sources in two groups, neither "better" than the other. There's the people who are already out there and covered and well-known experts on the topic, and then there's people who are maybe in your community (local, online, etc.) and have their own deep experience but don't have source-seeking creatives beating on their doors. Both groups are valuable in their own ways.

Sometimes it's the less talked to, more accessible people who will give you the most colorful and interesting information. They haven't been questioned to death on the topic so they're less rehearsed, and typically have stories that you won't find elsewhere that you can use (with their permission) to add some extra life to what you're working on. Depending on their particular credentials, they may or may not help you reach a level of credibility you need in order for your work to succeed (in some fields you really need to have internationally-known Ph.D.'s and whatnot on your source roster) but they're also less likely to have a personal agenda in sharing with you, in my experience. They might just be tickled you asked.

Then there's the rock stars of various fields. If you've already been doing reading/viewing on the topic, just look back through the works and see who was interviewed or thanked for their assistance. Unless you're doing a high profile project, though, these folks are probably too pressed for time to give you input. It depends on the circumstances and your timing. Again, I'm not a huge fan of using the same source everyone else does unless there really is only one expert to go to. Discussion can stagnate if only one expert is ever consulted.

On that note, here's some final suggestions for tracking down sources that may have the time to answer your questions:

• Professional associations - Track down professional associations serving the field of interest. Do they offer discussion forums that are open to the public? If so, you might post there. If not, you can write the association, explain what you're looking for, and ask if they can suggest anyone. Such associations also offer a member listing on their web sites, and may publish magazines and/or journals you can look at both for research materials and for people you might want to contact.
• Serious hobbyist sites - There's occasional hobbyists and then there's people who live and breathe a topic. Depending on what you're working on, you may not need a credentialed or titled source. Even if you do, hobbyists will have professionals that they admire and can recommend. They may even be able to give you an introduction.