Worry stones are designed to bring a sense of peace when touched. Its main purpose is to release stress. They fit perfectly between the thumb and forefinger. The gentle motion of massaging one's thumb back and forth over the stone provides a point of physical contact that can provide therapeutic and psychological benefits.
The blue jasper stone allows a solid anchoring. It is also a stone that would bring the will to undertake one's dreams.
Keep it on you, in your pockets or in your bag so you can take it out and use it anytime. Use it when you feel nervous, when you need to relax or change your mind.