Do NOT grab her by the waist

Someone mentioned to grab her by the waist, tickle her ribs and then she will fall into your arms.

If she is your girlfriend already do this. If she is a normal girl, she will feel uncomfortable about if her waist feels fat, hate the tickling and not be comfortable to be basically grabbed and groped.

Whoever wrote to grab her waist, tickle her and then let her fall into your arms is hoping you will fail.