I know it's pretty simple, but I have never made an ice ring for a punch bowl before, and decided to give it a try.
For the ring, I used canned mandarin orange segments and pineapple rings. I layered the oranges on the bottom and then the rings on top. I added just enough water to cover the fruit and froze for about two hours. Then I added another couple of inches of water and froze overnight.
To remove the ring, I just used the hose attachment on my sink and sprayed the bottom of the pan with hot water and it slid right out. The ring lasted about three hours in the punch bowl.
For the small cubes, I added an orange segment to mini-muffin tins. Again, I added just enough water to cover the fruit and then froze for about two hours. I then filled each of the tins up and froze overnight. To remove, I sprayed the bottom with hot water, and they popped right out.
The ice ring took up so much room in the punch bowl that I added these to ice in my bowl to fill up cups.