Twist the strip a full 360 degrees (or a multiple of this) and tape the ends together to make a ring. The ring should not be a moebius, which only has a 180 degree half twist (or any odd number of half twists). Lastly, cut the ring right down the middle, and you will get two linked rings. If you twisted the strip more than one full twist, the rings will be twisted together.
Another method is to cut down the middle of a moebius strip, and again cut down the middle of the resulting loop. There are still other methods that all involve cutting twisted strips.
Here's a related link from mathworld on moebius strips