... I flew a lot with PP-VFR safety pilot friends to accrue the experience,
and paid for only the 15 hours CFII time required. That was more than
enough CFII time. So long as you don't develop bad habits, safety-pilot
time is good enough for you to learn yourself how easily you can kill
yourself if you're not good enough.

In my opinion, it's rare that an instrument student would do well with just
the 15 hour minimum CFII time. And avoiding bad habits is critical. For
those who do decide to practice with a safety pilot, I strongly advice
coordinating the flights with your CFII. Have a specific plan and goal for
each flight, and don't do more than two or three practice flights in a row
without flying with your CFII.

Barry, CFII and former instrument student