Here’s a tip: When you’ve run out of things to say, ask your match the other canned 1st or 2nd questions. See Complete list of canned 2nd questions in eHarmony.
When I find a match interesting enough, I create printouts of the About Me page and our communications. Finding interesting things to ask or discuss becomes easier. As I have so many matches these printouts help me tell one match from the other! (This reminds me, I have to have a filing system soon.)