Today's families tend to schedule more than in years past, leaving kids with less freetime and less down time. Although the efforts are well-intentioned, to provide opportunities for kids and keep them out of trouble, it actually contributes to stress in kids.
Michele Kambolis, renowned child and family therapist, speaker, and author of Generation Stressed: Play-Based Tools to Help Your Child Overcome Anxiety has seen a significant rise in young patients with severe anxiety and points out that parents are also more stressed than their peers. In the book, she provides many ways to help parents work with their children to overcome anxiety.
Play therapy can be great. I've had several friends take their kids to play-based therapists with good results. The advantage of some of these play-based tools is that they are less intimidating to kids and can be incorporated into regular family time. Not all of the techniques in the book are truly play, but they are all meant to be gentle and positive, with visual or tactile representations of releasing stress and anxiety. There are also really helpful chapters on when to bring in a professional, and what not to say to a child struggling with anxiety. Some of the things we as parents are tempted to say (like "it's not that bad" or "don't worry") can actually have the opposite effect, depending on the situation.
The book is well-written and helpful, whether your child has major stress and anxiety issues and you're trying things at home in cooperation with a licensed therapist, or you just see issues begin to rise and you want to give your child tools to handle it appropriately before it boils out of control.