You're at a party or a conference or just walking along the street when you see someone you would like to talk with. It might be someone you've admired from afar, someone who might be a good customer or investor for your company, or someone you simply like the looks of. You struggle for the right thing to say that would get the two of you talking, but before you can come up with anything good, the person has moved on or gotten involved in a different conversation and the moment has passed.

If this has happened to you, it needn't ever happen again. You can gracefully start a conversation with absolutely anyone, anytime. There's only one secret: Say something the person will be happy to hear.

With that in mind, it should be very clear that a political comment (unless you really know the listener's politics), anything that could be seen as offensive, and most complaining is off the table. So is any kind of gossip.

Instead, walk up to the person, speak pleasantly, and pick the most appropriate of the conversation-starters below. There's a decent chance you'll be chatting away in no time. At the very least, you'll likely be able to get contact info you can use later on.

1. Make note of something pleasant.

"This dip is delicious!" "Nice turnout for this event!" "Did you hear the keynote? I thought it was great." There's something positive to say in nearly every situation, so find it and say it. Don't say something negative because it's much too risky. "I thought the keynote was boring," could backfire if the listener turns out to be the keynote speaker's cousin.

2. Comment on the weather.

The one exception to the no-negatives rule is weather. If you're in the midst of a heat wave, cold snap, or torrential downpour, remarking on the unusual weather is often a good way to start a conversation -- it's a shared experience, one that both you and the listener are having. If it's a particularly lovely day, that's a good way to start too.

3. Ask for information.

"Excuse me, do you know what time the next session starts?" Even if you already know the answer, asking for information can be a great way to start someone talking with you, because everyone likes to feel helpful.

4. Ask for assistance.

"Could you reach that item on the top shelf for me?" "I dropped my ring and I think it rolled under your table. Would you take a quick look?" Requests for assistance are another way to make someone feel helpful. Just make sure whatever you ask for is something the listener can provide without much inconvenience.

5. Offer assistance.

You won't often find yourself in a situation where you can help someone you're dying to talk to, but if it happens, don't miss your chance to be of use. "Can I help you carry that large box?" "Do you need a seat? There's a free one over here." "Would you like a program? I happen to have an extra." The listener will be inclined to like you and trust you because you've helped out.

Be careful not to be intrusive or excessive. "I couldn't help overhearing that your credit card was declined -- would you like to use mine?" will do more harm than good.

6. Solicit an opinion.

"What did you think of that speech?" "Did you get a lot out of this workshop?" "I see you're drinking the special cocktail. Would you recommend it?" Most people like knowing that others are interested in their opinions and will be happy to respond.

7. Mention a mutual acquaintance.

"Did you used to work with Roger? He and I have done several projects together." Naming someone you both know will tell the listener you are part of his or her extended social circle. Many people will begin thinking of you as someone they know, or should know. Be careful, though, that their relationship with your shared acquaintance is on good terms -- you don't want to say you're best friends with someone only to learn your friend and the listener are in the midst of a legal dispute.

8. Bring up a shared experience.

Does the listener come from the same town or region as you? Did you attend the same high school or college? Have you both worked for the same company or boss? Do you both love to scuba dive? Any common ground is a good way to start someone talking, especially if you use it as a reason to ask for information or advice. "Do you know what happened to John who used to work there?" "Do you prefer warm-water or cold-water diving?"

9. Praise the listener.

This works when you're wondering what to say to a celebrity, a noted VC, or someone prominent in your industry or company. You'll never insult someone by saying, "I really love your work," or "I thought your last blog post was very insightful."

Three caveats: Don't fawn, don't make the mistake of critiquing the listener, as in "I thought your most recent movie was much better than last year's." And only offer praise if you genuinely mean it.

10. Compliment the listener's apparel or accessories.

"That's a really unusual necktie. Where did you get it?" "That scarf is a great color on you." Most people like it when others appreciate their taste, so they will likely want to engage with you.

Don't comment on the listener's own physical appearance -- having a stranger or near-stranger tell you that you have beautiful eyes is more creepy than anything else. The exception is hair. If the listener has recently changed hairstyle or had a haircut, it's fine to compliment that. (But if someone started coloring hair to remove the gray, best to keep that comment to yourself.)

11. Simply introduce yourself.

This won't work in every setting but in many cases, if you truly can't come up with an appealing conversational gambit, you can try the direct approach. Walk up to the person, stick out your hand and say, "Hi, I'm so-and-so. I just wanted to introduce myself." The fact that you went out of your way to meet will make the listener feel important. It will probably make the person want to talk to you, as well.