When I first started in the event business and a client wanted some type of centerpiece, my first thought went to something tall, big, and lots of flowers.  But in this case, she wanted something simple, small, and minimal flowers if any.  So back to my desk and drawing a blank, what can I give her?  well, in surfing around I found lots of ideas and some did not even incorporate ANY flowers but instead candles, which I love and is always a hit on a table.  So my advice to you, when thinking of centerpieces, think of your theme and work around that.  Add colors and shapes, candles, balloons, pictures, anything that will compliment your taste and theme.  Here are a few examples that I found online, use these beautiful setup to draw your own inspirations.