Step 2: Bend the two suspended shoelaces into an N-shape and place them on top of each other.
Step 3: First, the N-shape on the right side bypasses the overlapping part and returns to the original position.
Step 4: Turn the left N-shape around the overlapping part and return to its original position.
Step 5: Tighten the two N-shapes to form a slipknot, so that the knotted shoelaces will not loosen again.