Inspiration is the first step towards creation of a product or service. Observing how things and people work in the real world (which might require living with local communities) is very helpful for drawing inspiration. The example of the use of the positive deviance initiative, where the problem of malnutrition in Vietnam was solved by discovering the solution within the same community, is a good one of drawing inspiration.
In the Ideation space, the authors highlight the importance of letting ideas flow (while deferring judgment) till the end of brainstorming sessions. Organizations often restrict choices while ideating on projects, which is easier to do in the short-term. However, divergent thinking and more ideas are what lead to disruptive solutions and are beneficial in the long-run. It is also advisable to have multi-disciplinary teams when collaborating.
The last space is Implementation, which is the key to the creation of the final product or service. In this space, prototyping is extremely important. Testing within a small and well chosen sample set of users can help create a revolutionary product.
If you want to learn Human Centric Design (HCD) and use it for innovation, you can use the IDEO designed HCD Toolkit, which helps organizations understand people's needs in new ways, find innovative solutions to meet these needs, and deliver solutions with financial sustainability in mind. The toolkit was created in collaboration with the Gates Foundation and non-profit groups IDE, ICRW and Heifer International.