Nothing really, Anyone is welcome.
No need to make up any fancy conversation openers, just "Hi" is enough (of course saying something more than just "Hi" is always a big plus, but yeah, it's up to you :D) . Though, it would be always nice if you would had read my profile or some bits of it before contacting me, but it's useless to complain here since those who aren't going to read this aren't going to read this.