Screeners pick which calls get on the air, so respond succinctly and coherently to their inquiries.
Make it clear to the screener that you have something specific, different, and intriguing to add to the subject under discussion. It's best if you have an exciting personal experience to recount. Once on, quickly say something germane, then move to whatever you really want to discuss. All letters to the editor are for publication and may be edited for length and clarity.