Mary Poppendieck applies these lean rules to software teams. Practice these concepts and great things will happen.
1. Eliminate waste: Spend time only on what adds real customer value.
2. Amplify learning: When you have tough problems, increase feedback.
3. Decide as late as possible: Keep your options open as long as practical, but no longer.
4. Deliver as fast as possible: Deliver value to customers as soon as they ask for it.
5. Empower the team: Let the people who add value use their full potential.
6. Build integrity in: Don't try to tack on integrity after the fact – build it in. (Think test first)
7. See the whole: Beware of the temptation to optimize parts at the expense of the whole.
Here's a key point I gleaned after putting together concepts from several speakers. There's a confluence of technologies and development techniques that delivers a competitive advantage to anyone who masters them.
I've worked with several product managers who never really grasped the concept of a minimum viable product (MVP). They often over engineered user interfaces or added features the customer never wanted or used.
It usually took one failed product before they caught on and started asking me how this MVP thing works.
It's all about creating learning loops with your customers.