How many of us give much thought to the quality of our friendships or the ways we could be intentionally nourishing our friendships? Turns out there’s not only an art and a science to how we create really good friendships, but there’s a formula to the process as well. Shasta Nelson, author of “Friendships Don’t Just Happen” and “Frientimacy: How to Deepen Friendships for Lifelong Health and Happiness,” has truly become one of the world’s leading voices for friendship.