I picked up the pine cones, she got some extra white candles, and we used a green table cloth and gold chargers she had. Very affordable and simple, but strengthened by the fact that we ran the same theme all the way down the table. The most common mistake I see is when people place items sporadically down the table or fail to choose one theme and continue it all the way. To create a striking effect, you'll probably need to buy double the amount of centerpiece supplies you think you'll need. This will ensure a full and festive table.
P.S. This was a day or two before Christmas Eve. Don't worry, we had silverware and glasses the day of the feast :)