Do you mean people not handing down tribal knowledge? Or preventing something from becoming tribal knowledge to begin with?
If the goal is to avoid something becoming tribal knowledge, then don't consider a project complete until it has been documented and a completely different team has deployed and supported the project without any need to talk to the engineers/architects/developers that created the project. There will always be feedback loops to improve a project, but if a completely unrelated team can't deploy and support something, then you have tribal knowledge that has not been communicated in documentation, including self documenting code and/or videos. There is much more to this of course and hopefully others here will add more tips.
If the goal is to avoid something becoming tribal knowledge, then don't consider a project complete until it has been documented and a completely different team has deployed and supported the project without any need to talk to the engineers/architects/developers that created the project. There will always be feedback loops to improve a project, but if a completely unrelated team can't deploy and support something, then you have tribal knowledge that has not been communicated in documentation, including self documenting code and/or videos. There is much more to this of course and hopefully others here will add more tips.