You can go to their first posts that are vanity threads, and mention that vanities aren't all that cool. Then you'll be jumped on by well-meaning Freepers that think you're being a grouch and not welcoming the newbie.
Personally, I'm almost ready to post a vanity about my upcoming dental teeth-cleaning appointment and I'd bet it would get 100+ sincere replies.
Post that vanity and I'll send ya here ;^)
I wish there was a "time limit" on your tenure before you could post.