1. Be very honest in your profile, at the same time be who you want to be in a new R. This will take you out of your comfort zone, but will probably be a much more authentic you.
2. Don't explain away red flags.
3. Many people go to dating sites to hook-up. They are easy to spot. "Hey baby, you so sexy. Want to do something (right now, at 2 a.m. in the morning."
4. People living with their spouses are NOT available. Period. End of story. They are lying to you and probably themselves if they say they are.
5. People who celebrate holidays with ex-spouses or STBX spouses are not emotionally available. Likewise, people who are still constantly evaluating how "nice" the "X" is to them are not emotionally available.
6. People who are annoying, bad spellers, dim-witted, off-putting, too aggressive online will NOT be better in person.
7. Don't waste time. If it seems worth meeting someone, meet them within a week.
8. The guy who says he wants to meet you, is crazy about you, can only talk at odd times, and hasn't managed to meet you in a month is NOT GOING TO.
9. Living with one's "X" GF or BF... See 4.
10. Phone sex, sexting, and so on are status quo these days among dating couples. But, as an introduction, well, see 2.