Allow at least 24 hours for the ice ring to completely freeze.
You will need:
Pour a small amount of chilled water into the bottom of the pan to a depth of about 1/4". Place the pan on a level surface in the freezer and allow water to set until slushy (not frozen solid). This doesn't take long so check pan frequently. The water should just be slushy but firm enough to hold the decorations in place.
Remove pan from freezer. Working quickly so that the water doesn't melt, place berries and/or lemon slices on top of the ice in a decoration of your choice. You may need to do this in stages if the water begins to melt. When all the fruit is placed in a decoration you like, return pan to the freezer until water is completely frozen. If necessary, allow the water to melt slightly and reposition the fruit if it has moved; re-freeze. Meanwhile, keep the prepared punch chilled in the refrigerator.
Pour a small amount of chilled, prepared punch into the pan; return to freezer until frozen.
Repeat the above step until the fruit is completely covered with frozen punch.
Pour remaining chilled punch into the pan; return to freezer until completely frozen.
At serving time, dip pan into a bowl of lukewarm water for about 1 minute. Carefully turn out mold into empty punch bowl. Pour chilled punch into bowl, and serve.