You need to boundaries to be created by a well-known, impartial algorithm rather than a person. And you pay a committee of academic programmers from other count

You need to boundaries to be created by a well-known, impartial algorithm rather than a person. And you pay a committee of academic programmers from other countries, with no political ties to the country where it's intended to be used, to design the algorithm. And you use the same algorithm forever rather than changing it from year to year. That solves the gerrymandering problem. Of course, it doesn't solve the problem of getting whichever party currently benefits from gerrymandering to agree to switch to the neutral algorithm.