Gates, not milestones
A milestone reports progress; a gate decides whether to continue. Defining what must be true to pass each gate, evidence, owner, measure, keeps a project honest at the points where it would otherwise drift.
Evidence produced in flight
Test results, evaluation runs and acceptance mapping are outputs of the work itself. Collected as they are produced, they are cheap; reconstructed at the end for a review, they are expensive and less credible.
Release small, release reversibly
Smaller releases fail smaller. Versioning, rollback procedures and a documented change record are what allow a team to move at a steady pace without accumulating operational risk.