Step 3: Make a place to attach the shower ring to the curtain
On bottom edge of your curtain (at the end away from the drain), fold over and sew down the tip of the corner. You are making a tunnel for a removable shower ring.
If you use a solid vinyl curtain, fold over that corner and use a paper punch to make a round hole through both layers - about an inch in from all the edges. The point of making a round hole is to prevent making a weak point where the ring could rip out.