Hi kristijoy. All the swaps I've participated in have allowed different fabrics with the same pattern but I believe most people just make 4 identical blocks. I know that's what I do. I make a lot of applique but I plan to do some pieced blocks this time around. If you go to the fall block swap and check out the last page, you'll see the snowflake I make for my guild BOM. I plan to make 4 of them with a blue background.
Welcome to the fun!