This is a simple question but the answer can get really complicated and only people who actually, build, manage and maintain a healthy static will appreciate the time and mental effort it takes to achieve. I will go over some basics to help show that if you follow those you find that most of your issues are solved for you.

First you need a clear measurable objective: "I want to clear all wings in X time" for example. The reason for this is to make sure you yourself have a solid idea of what you want to achieve when raiding. If you would just like to clear the raids as fast as possible but you really want your mate who works 50 hours a week and only logs into raid, never practices, doesn't know a thing about his dps and clicks that yellow bar over his hp to dodge then you obviously will have to set up your group to accommodate for yours and his needs.

Second you need to develop or adopt tactics, builds and have them readily available for yourself and your team or at least make sure they know where to refer to.(don't ever assume people are aware of current metas, foods, tactics etc). This step should be catered around your level of commitment and your priorities and it is always important that you review and update.

Third recruit and maintain a roster that falls in line with your expectations. This step is incredibly important and it is almost entirely down to you how much time and effort goes it to this. If your objective is to raid with the people you are with now and all else be damned then you are relying on each individuals level of commitment which can go either way. This situation however leaves you in the position of "we are all just mates raiding together" rather than you leading. The end goal for a good team is that it manages itself with little as possible micromanagement during raid hours.

Lastly(and to keep this post short, I could go on forever) Active engagement with all your team before and after the raid is in my eyes the lifeblood of a good team. From recruitment to telling them "thank you for raiding with us best of luck " you always want to keep track of who is performing well and not so well in order to provide them with feedback to improve and feel valued. Be open, honest and diplomatic. Remember you want them to improve, that is your end goal so employ the tools that are right for you and your team. I, for example, use recordings and encourage my team to do the same. It makes the whole process alot smoother when you have recorded evidence of a team member messing up or not performing how you expect them to. A side note to this is that try to be as clear in your instruction as possible. Don't rant on for days, employ methods best suited to your needs and the people you are trying train or review.

To summarise: Be clear about what your goals. Have an accessible pool of tools and resources to achieve these goals. Build and structure a team that in the end manages itself. Communication is key. Try and have fun and remember its only a game.