I saw this amazing idea at Big Red Kitchen. She did a gorgeous layered centerpiece, but for the sake of time, I did something very simple. Check out her blog and see what she did. She also has some great looking recipes.
Start out with a glass container. I used a vase. Place a pillar candle into the container. Then scrunch up some plastic wrap down into the bottom. I used a knife to get it down into the corners:
Then add enough water to cover it:
It immediately starts to look like partially melted ice:
Add some fresh greenery and berries, and you are done. And it will keep looking icy wonderful regardless of the temperature!