Top 7 ways to curb schedule burnout for kids

My children could never catch up with my friend Margaret's children. Her children were always enrolled in at least one music lesson and one art lesson, while playing two sports and participating in Scouts and church activities. My kids seemed content with one lesson each and several afternoons of TV and Xbox. Looking back at her childhood, clinical psychologist Valerie Hale, Ph.D., said she preferred participating in a lot of activities because she didn't want to be home alone while her mother worked. Yet today, in counseling children, she often recommends no more than one or two after-school activities a week, and she suggests less is more. While choosing a child's activities is certainly an individual choice, what guidelines do professionals suggest parents consider to avoid burnout and keep activity participation stress-free?