Learning how to open and close jump rings in the correct manner is not hard, but it is an essential skill to learn.
The first thing to know is how NOT to open them. A jump ring should be opened like the ring on the right, not the one on the left. The one on the left was pulled or stretched open and will be almost impossible to get it back into the original round shape with the cut ends flush and even.
Positioning the pliers on the jump ring: To open and close jump rings, two pliers are generally used, either two flat nose pliers or a flat and a chain nose plier. Where to grasp the jump ring with pliers: The first photo shows the jump ring opening a bit off center between the two pliers. This will work, but the closer to centered the opening is between the pliers-second photo, the more likely the twist in the jump ring will be half way around the ring, which is ideal.