Experimentation guidelines allow you to quickly and safely tackle challenges and capitalize on opportunities, and get closer to your shared vision.
They are an example of a situation where structure sets you free, because once you have guidelines for running experiments, everyone in the organization will be free to run their own experiments without having to ask permission on a case-by-case basis.
Guidelines can be very loose (such as a set of values to work by, e.g. “Move fast and break things”), or they can be more structured, such as a RFC process that must be followed to try new initiatives.
Your experimentation guidelines should balance advocacy and inquiry: they should give people a chance to make their point (advocacy), but they should also ensure that this is done with objective statements and data, and that any known/less known assumptions come to the surface during the process (inquiry).
Having experimentation guidelines that follow these traits also allows people to explore ideas from different angles before executing them (because ideas need to be grappled with).