The errors your team makes will be specific to its structure and goals. However, there are some mistakes that everyone makes.
Not Asking for Help
No one has super powers — and that includes leaders. You have skills, but the essence of teamwork says that you can't get everything done yourself. Take advantage of the resources available to you. Empower team members and delegate. In addition, when you are beyond what you know how to do, find people who can provide the necessary information or expertise to let you succeed.
It is important to deal with change. One aspect is being flexible about the way in which your team achieves its goals. Organizations may change budgets or shift deadlines. Environmental factors can suddenly make a strategy unworkable. Shift with conditions as necessary; the more you try to stay with what no longer works, the bigger a mistake you will create.
Forgetting Your Origins
When leadership involves an official position of authority, there is the risk of thinking that you're better than the other people you're dealing with. That is foolish. At many smart companies, the top salespeople make more money than the CEOs because they are the ones who help bring in all the revenue. People in power aren't necessarily more important than those who aren't. Be thankful for what team members do and their willingness to help. Don't talk down to them, and don't think that they are there to simply follow orders. They are there for the same reason you should be: to help the organization achieve its goals.