I'm quite sure I've posted about this before, but I'm a big fan of old school correspondence. Like handwritten, put in an envelope with a cute stamp. I even use cute stamps for my business correspondence (because wouldn't you rather open a letter with a cute stamp rather than a plain old flag?). I always look up the new stamps that will be coming out each year. Look what I found for 2012!! I know, right?
Look out clients and friends - there may be a letter or card with a cute stamp in your future!