I think there are a number of effective ways in which School administrators can support their teachers.
1. Provide a clarity of purpose to the community. If you can get your community of parents on board with understanding why a blended approach is important for the School and their children then I think this gives teachers the confidence and space to develop their practice and try new approaches.
2. Build a community of practice. At Melbourne Girls Grammar, we have implemented a blended learning paradigm in Year 9 and on a weekly basis we have drop in lunch meetings with the teachers. This gives them an opportunity to share ideas and strategies and tell each other what is working for them and what they are struggling with.
3. The other things we do that we feel is supportive is we talk to our girls about their experiences. Our girls are great with letting us know what works and what doesn't. we collect this feedback formally and informally and we feed it back to the teachers so that they are affirmed or with action items that they can build into their practice to improve the experience of the girls.
There are plenty of other strategies we use, but we have found these to be particularly positive and supportive.
As a leader and leader I have a few words of advice to share:
I feel that direct experience is key. First step would be to visit some schools/classrooms with well established approaches and see what the experience feels like as a student. Then try teaching some of the lessons yourself (perhaps shadowing an existing teacher with relevant experience). Then (and only then) see about trying to implement it in a school where you are an administrator. This helps to follow the rule of "Don't ask anyone to do something that you wouldn't do (and/or haven't already done] yourself."