A Great Tip from Paul Bennett:

So try this. Buy a train ticket home for the weekend. Not your current house, but home-home, to your parents. Now sit them down at the kitchen table and, in 50 words or less, tell them what you do for a living, what product you make or sell (or if you're a consultant, what process or deliverable you sell), and what's good about it. Don't use weird words or anything with lots of syllables. Don't quit until they understand you. I told my mother once that I worked in Conceptual Marketing and I swear she thought I had joined a cult.  Remember what you said. Now go back to work, and apply this principle to your job. Simple stories, truths well told, no made-up nomenclature and gilded lilies. It's more clever to be simple, don't forget that.