VirtualDatingAssistants' Valdez warned guys against posting photos of themselves with strippers or with their shirts off. It's "inappropriate," he said.
Women, he said, should stay away from "funny face" photos and too many party shots.
"A party girl is fun for a night but most of the guys aren't looking for something long-term with those girls," he said. Just like marketers shape a branding campaign with their target audience in mind, he said online daters need to post photos that align with the potential mates they're trying to meet.
3. Search for partners strategically.
Don't spin your wheels looking for people who aren't looking for you.
"Most people spend time looking for the person they want, not who's looking for them," said Katz. "What you look for is irrelevant if they're not looking for you back."
For example, if you're a woman over 30, seek out men who want a woman over 30. Don't pin your hopes on the guy who seems perfect but explicitly says he's only interested in women 29 and younger.
Or if you're a man in San Francisco, don't expend too much energy flirting with a woman in Denver whose profile indicates that she's not interested in out-of-towners.
Many sites have so-called mutual match systems that help members search for those who would find them interesting. Katz and others suggest online daters take advantage of these systems to most efficiently connect with potential dates.
It might mean that you have to adjust your expectations but Katz said, "Trying to convince someone to be open to you is a waste of your time."
He added that it doesn't mean that people don't sometimes connect with someone who didn't fit the criteria they originally selected. But it's the exception, not the rule.
4. Ask for feedback.
Before you publish your profile, solicit some feedback.
"Get opinions from friends," said Valdez, adding that opinions from the opposite sex are especially important.
In addition to asking honest friends for their thoughts on your picture and profile, he also suggested reaching out to members of your online dating site who live outside your area. For example, if you're a guy in Boston, send your profile to women in Chicago who share the characteristics of your ideal date.
"For a lot of guys, they create a profile and there's a big turn off but they just don't notice it," Valdez said. Politely asking other women outside your area for their opinion could help eliminate those turn-offs before women in your area have the chance to write you off.
5. Write a winning first e-mail.
Since the point of the e-mail is to elicit a response, experts say you'd better start by paying attention to the subject line.
"It's just like a direct marketing campaign. If you don't get a click-through, you're done right there," said Valdez.
"Hi" and "Hello" should be automatically disqualified, he said, as those are among the most common words in a subject line.
Instead, he suggested starting a thought and then not finishing it as well as including something the person mentioned in his or her profile.
For the e-mail itself, Katz had this to say: "The key to writing the first email is to change your goal."
Don't try to "sell yourself" or impress someone in the first e-mail by listing your best qualities, he emphasized.
"Your goal is to make someone smile," Katz said. "You make someone smile in three or four lines, they know what they're supposed to do next."