We've been creating design principles for our clients for many years and have learnt that half the battle is defining them, the other half is about getting stakeholders' buy-in. There's a balance to be had between being collaborative and being quick - get this balance wrong and your design principles may not take off in the way you hoped.
There are a number of best practices we follow when creating design principles with our clients:
Before engaging with a broad group of collaborators to create your design principles, be sure to:
You'll then be able to keep your collaborators on-track with a very tightly defined brief that almost feeds them the answers. If the brief is based on user needs (generated by research) and business goals (communicated by execs) then it aligns everyone really well.
Would there ever be a scenario where someone might not want to adhere to a design principle you create? If so then you're OK, if not then you're being too vague. For example, a principle like 'caring' would pass the test because many brands might not want to be caring; a principle like 'good experience' would fail because no one would ever say they don't want this.
Apply this test ruthlessly when creating your design principles – be sure to introduce it at the start of your workshops and get your collaborators to check each other's suggestions. The 'not test' is a brilliant test which you can apply to many aspects of your work and many things that you create.
There are many ways to engage with your collaborators and the right way to do so depends on your culture, the people you're engaging with etc.
You can start by asking people to anonymously submit design principles (based on the context and brief you define) – once you get the full list, further narrow down the context and work out roughly what you think the outcome could be. Then, run a workshop with key stakeholders with this narrower context which increases the chances of getting to an outcome you're happy with.
The more narrow your brief, the more likely you are to get to a great result (provided the brief is based on user needs and business goals which collaborators can't disagree with).