I love this article from our friends at AllEars.net that offers up some of my favorite suggestions, like building in down time and alone time, making ADRs far in advance, and letting everyone get in on the planning. If you're looking for some great tips, check it out!
https://allears.net/2019/12/01/the-best-disney-planning-hacks-for-traveling-with-a-large-group/