Strict WIP limits, all non-trivial projects need two human collaborators who are both responsible for understanding and signing off on the project plan, docs, code, test strategy, etc., and regular sync-up meetings.
This is actually in line with a well-established Six Sigma practice. When you've got a poorly performing value chain, the first thing to do is find out which step is struggling and then force the step immediately before it to slow down. If the reason why isn't obvious, search for a clip of the I Love Lucy chocolate factory scene on YouTube for a perfect explanation.