Firstly make sure your container is clean and free of labels.
Cut one circular piece of Aluminium, slightly wider than the diameter of your container. I used a bowl because it was big enough for my needs. Cut slits around the edge of the circular Aluminium piece, these are so you can overlap them. When you've done cutting your foil it should look like a flower head with petals. Curl the petals of the Aluminium until it looks a bit like a bowl. Now glue the base section in place, making sure you go partway up the wall.