The world is full of team motivation theories. Many are interesting but difficult to apply in the day to day activity of working life. Successful teams are those that function at a high level of capability. Knowing you’re part of a great team is pretty inspiring in itself.
Because you’re leading a group of highly capable individuals you have to continue to excite and inspire them toward new challenges. It keeps that sense of motivation at the level you want.
Never tell people how to do things. Tell them what to do and they will surprise you with their ingenuity. Surprise people with real challenges. Take them aside and hand over meaningful, interesting work. Use stretch goals. Some people don’t always realize what they’re really capable of. Get to know what motivates each individual. Sounds obvious, but some leaders don’t do it.
Challenge people and get them deeply involved in the work they do. Show them what your issues are. The angle from which you’re looking at problems.
Build an empowered team. An empowered team makes decisions that have real impact on the success of an organization.
Lastly, getting a team to a stage is a big achievement for a leader. Keeping them there is another thing. One action that will certainly help you is praising the good decisions they make. Failing to do this, or only mentioning the occasions when they get it wrong, will soon puncture the empowerment balloon.