Is the dinner going to be formal?
If it is a formal dinner, it might be nice to seat the host and hostess at the head of the table and the guests of honor to their left. If it is less formal, you might leave the heads of the table empty and sit in the six seats along the sides. If you do that, you might consider skipping a centerpiece and placing your decorations at the ends of the table instead. In the middle of the table, place a long but low row of candles that will flatter all of the guests. This way, all six of you will be able to see each other clearly.
There are so many other tricks to help you with seating arrangements in my new book, Tablescapes, so please order your copy today!