When zeroing off the machine bed and putting my machine at the zero x y and then loading my Aspire design that's set up to run using the machine bed as zero. Where do I put my machine at for the z height before starting?

When zeroing off the machine bed and putting my machine at the zero x y and then loading my Aspire design that's set up to run using the machine bed as zero. Where do I put my machine at for the z height before starting?

The answer to this student question can be viewed in the 1/31/2023 Q&A Meetup at the 00:00:32 timestamp(must be logged in to watch).