This is just inspiration for a simple but elegant centerpiece that is easily put together.  Use oasis that has been soaked and placed in an oblong or rectangular container with a little depth to hold water.  I used White Pine branches because they are soft and easy to work with, red roses, red twig wild dogwood for height and some artificial sparkly pomogranates.  Real pomogranates could easily be used as well, since they have longevity. Use your imagination, just remember to vary the heights of your elements for eye appeal.