1. Keep quiet about your candidates. Don't forward your search status reports to anyone. If you want data from, say, a partner in your venture or PE firm, just call and ask about what they know. Even partners can make a mistake, forward a note with a bunch of resumes and biographies, and then the data goes viral. That's just bad hygiene, possibly illegal and risky. Big search firms tend to brag to the press about who they're talking to, which is spectacularly stupid on a number of levels, most of which are abundantly obvious. Clueless, big company Boards take that press, eat it up and say, naively: "look at who those guys get to talk to!" Meanwhile, the "candidates", most of whom never even returned a call from the Korn Ferry partner in question (an example), are thinking "who the hell's using my name in vain?" Too many examples to count, point is, keep quiet! Recruiting is about discretion and not chest beating.
2. Do very quiet early referencing on key people, contextually of course, and don't let people run off half cocked checking around because they've got nothing better to do, running their mouths off about who they're talking to. Word travels FAST. And people will wake up to who's around, who's open to things, etc. It is a call to action when, say, a PE or VC partner calls another one for a reference on a successful CEO they might have backed. You're inviting competition to act more quickly. Big mistake. Save it until the last minute, but know that you don't have any likely land mines before that stage, so you don't have to blow up the project and start over. Re-capping: don't wake people up to your candidates until you absolutely have to, in referencing or bravado.
3. Don't talk to the press. Enough said.
4. Stay in close contact with your candidates every week--at least the top 3. Spend the time to really understand how they're thinking about the opportunity you're discussing with them. Does it really fit their life plan? Are there motivations coming from a healthy place? Listen, don't just sell. You can close more people by listening than by selling.
5. When you have a "live one," be agile. Above and beyond all other things, don't let a high overhead process (too many people interviewing candidates, for example) bog you down and lose people. Get to a yes/no within 2-4 weeks. Healthy for all.
Good luck!
