Gently wiggle the zipper pull while pulling up.

This can help to loosen the zipper teeth and get them moving again.

Rub a graphite pencil or soap on the zipper teeth.

Drop a single drop of baby oil on the zipper tooth

This will help to reduce friction and make it easier to move the zipper teeth.

Apply  beeswax or lip balm on the zipper teeth.

If your zipper is still stuck, you may have to replace it with a new one

Use plier to grasp and ease the zipper down.