I usually like to announce a song by giving a bit of background to it (who wrote it,what album its from etc).I only recently started doing this since me and our lead player started going out as a 2-piece (acoustic guitar and bass + 2 vocals) a la Mike Masse.(check him out on Youtube).I took it on myself to instigate a bit of banter just for the sake of keeping people interested in what we were doing.In N.Ireland there are many folk duos about who insist in giving each song,or tune,the full works IE who wrote it,why they wrote it,what they were thinking about after they wrote it and tend to go a bit far.I just think a little bit of insight,and hey,maybe a bit of trivia about the music helps to build a bit of closeness with your punters.
PS if you're ever unfortunate enough to have just one person applaud after a song,just say "Thank you for the clap".Usually raises a titter.