Congress doesn't draw any boundaries (except the state boundaries, which were drawn long ago). State legislatures do it.

Giving power to a nonpartisan group sounds good, but still, what principles are they supposed to follow? What methods? What procedures? What goals? Whoever does the dividing, there are billions of ways it could be done. I assume some ways are better than others, but how do you tell the difference?

There's only one principle I ever see in operation: Whatever method confers an advantage on MY party is a good one. (Or, whatever confers an advantage on YOUR party is a bad one.)

Does anybody know of an alternative?

If I were on a nonpartisan committee, and I wanted to do my best to be fair to both parties (not to mention third parties), and there were two proposals before me—call them Plan A and Plan B—how should I decide which plan to vote for? Flip a coin?