Your Role as a "Parent Coach"
Your role on the parent-coach-athlete team is as a Support player with a capital S! You need to be your child's best fan. unconditionally! Leave the coaching and instruction to the coach. Provide encouragement, support, empathy, transportation, money, help with fund-raisers, etc., but... do not coach! Most parents that get into trouble with their children do so because they forget to remember the important position that they play. Coaching interferes with your role as supporter and fan. The last thing your child needs and wants to hear from you after a disappointing performance or loss is what they did technically or strategically wrong. Keep your role as a parent on the team separate from that as coach, and, if by necessity you actually get stuck in the almost no-win position of having to coach your child, try to maintain this separation of roles (i.e. on the deck, field or court say, "Now I'm talking to you as a coach", at home say, "Now I'm talking to you as a parent"). Don't parent when you coach and don't coach at home when you're supposed to be parenting.