Most Important: Be humble.

You know how to program and do the technical design, but do not do that anymore.

Delegate the development/technical tasks to your tech lead/Sr Developer. Help/Suggest them if they are overloaded or lagging behind but don't impose your technical strategies. Delegate and delegate!

Keep everyone involved. Do not hide any information from team. Invite Sr Dev/QA/Tech leads to the meetings with clients(selectively).

Give importance to every team member. Involve them in decision making.

Finally, do all of the above based on the situations. Do not do everything all the time.

So...Manage all of this to become a good Manager!