Place votives on some or all of the tables to give the room a romantic feel as the lights are dimmed throughout the evening. The candles will also be a nice touch for all the pictures taken. Scented candles are a nice option as well.
You may really love the eiffel vases available but may not want to pay for floral arrangements for each table. You can alternate the vases and use other centerpieces as well.
This helps reduce the cost and looks great too!