I'll offer a few points, in no particular order:
A leader's job is to Direct, Unite, Inspire, and Support. If you're doing anything that's not in those categories - stop doing it!
Be the Group Commander, not a Super Squadron Commander. In the MSG, for example, it's common for the MSG/CC to try to be the super-SFS/CC or super-BCE or whatever careerfield he came out of - over-managing that squadron while giving the other squadrons in the group too little direction. Don't do that. Ever. Seriously. You probably didn't like it when you were a sq/cc, so don't do it to your people.
Be willing to tell the wing commander "I don't know, but I'll find out." We have an MSG commander who is simply the biggest control freak and data hog I've ever met. His squadron commanders literally spend 30-50% of their work week managing HIM instead of doing their jobs. He creates the very chaos and inefficiency he professes to try to cure.
This is driven by, I think, 2 things, which a good group commander will avoid:
1. He needs an enormous volume of information before he feels like he understands an issue or activity. No matter how much you try to provide the answers up front, he'll still come back at you with more questions. Providing more detail to allay his insatiable need for info merely provides more avenues for enhanced questioning.
2. He's afraid to be caught not having the answer to every question he might ever be asked. As a group commander, you've got to know what's generally going on in your squadrons and the rest of the wing, but you're not paid to know everything in detail or do your squadron commanders' jobs for them. If you don't know, man-up and admit it. And also give yourself a break because it's neither feasible nor reasonable for anyone to expect you to know everything.
As a general rule of thumb, think about the things that provide job satisfaction for you in a leadership position - having authority, being held responsible, encouraging and facilitating teamwork, solving complicated problems, developing the people under you to help them grow professionally and personally, etc. Then make sure you do nothing that deprives your subordinates of enjoying that same job satisfaction.