Read all the above and THINK about what has been written.
THEN practice. And THEN THINK SOME MORE. With some more practice after that, you'll get the hang of it ok. Understand what the likes of El Greko and Cassie are saying. Pay minute attention to every phrase and line - does it contribute something new or interesting or memorable to the song.
When you think it's finished, put it to one side for a while. Then practice it for performance - do the words come easily to the tongue or is it impossible for anyone other than a G&S freak to sing?
Then sing it to strangers. Listen and look for genuine reactions. Store impressions. Look for new ideas - write them down. Accept criticism as gracefully as you can (hard as that may be) and bear it in mind. It's a bit like giving birth - it bloody well hurts but it's soooooo satisfying when it leaves you and lives by the interpretations (often in ways you never considered)of others.
Have FUN. Work HARD. It's WORTH IT!
silverfish