With one specific person, I was feeling funny, so I sent her this message today:
Hi =) Standard comment about your appearance. Follow up mildly witty comment about my comment. Self-deprecating remark.
Declaration of shared interest gleaned from your profile. In-depth comment showing I am savvy purveyor of said interest. Query as to whether you’ve also seen or done a related thing.
Small pithy anecdote about something that happened the other day. Subtle tie-in with something on your profile. Blanket philosophical statement.
Expression of anticipation for your follow up reply.