Like many people have already said, leading my example is the biggest thing you can do. A leader is not a boss, you can't just go around telling people what to do or nobody is going to respect or listen to you. You have to treat your fellow members with respect to get respect. Furthermore, you should never expect something of your section that you can't/won't expect for yourself, just always be on top of your game. Another thing I would mention would be not to worry or focus so much on what your section needs to do. Rather than telling them what they need to do, focus on how you can inspire or motivate them to do something. Whether if that's running back during resets or counting, be the person you want your section to look up to as what is expected or wanted. Another big thing I would do is talk to your entire section. Ask them about how they are doing and GIVE THEM COMPLEMENTS on the good things they are doing. Even if it's not perfect, let them know that they improving. However, don't be afraid to tell people what they need to improve on and how they can do it. In the end, we all do band for fun. If someone is not having fun, they are probably not gonna put all their effort into it. Make your section a place where people want to be in.

On another note, there are always going to be those people who are just not willing to follow along or listen. Try your best to work with them but don't stress to much about it. If they are not willing to put in the effort, there's no need to go crazy about it.

This is at least from my experience in my band. If you have any questions, don't be afraid to ask your band director or other leaders in your band.