It took me 10 years to learn, from my oldest to my youngest, but figured out the best way was to head it off at the beginning. By that time I was done with competitive (travel) sports, which helped, but I started the season with a parent meeting. I told them up front I had three goals for the season: 1) I wanted ever kid to want to play NEXT year, after this season; 2) I could coach every kid, regardless of skill, to be better at the end of the season than they were now; and 3) Have fun at games and practices.
I also made a point to tell them that no one likes losing, but winning was NOT a major goal and if it came down to making a choice between a winning move or the one of the goals above, I would not take the winning move. So if you come to me with an argument, "we could have won..." it will be a waste of time.
As a result, I was able to have multiple low pressure and very enjoyable seasons, and ironically, we still were able to win 3 league championships (girls softball).
The best part was that my principals were tested multiple times, and thankfully I didn't take the bait. As a result, we got to see some very unlikely heroes make plays that common sense would have told you to not have in that position. Even if we had lost, I don't regret those decisions now.