You do not have to be the most creative person on the block in order to do this. You just have to follow some of these ideas and you will come away with a table that looks much better than it does right now, believe it or not.
For a rectangle table, you might consider just adding a runner right down the middle of the table. This sounds rather simple but the right colors and/or designs can really add a lot of flavor to the table and to the room.