Leave it to mathematicians
I read an article (sorry, don't recall where) which made an excellent case for allowing only an independent body of mathematicians to set district boundaries for elections. Politicians obviously shouldn't be allowed anywhere near the process: too stupid; too corrupt; in many cases, too both.
Perhaps it's time for a radical overhaul of election systems in many countries. In the US gerrymandering and the ridiculous electoral college system produce bizarrely unrepresentative results (Trump wins 3m fewer votes and is still elected??) and the UK isn't much better: boundaries are less of a problem, but the absurd first-past-the post system wildly exaggerates the influence of a relatively small number of "swing" marginal constituencies. The most recent example of course is that a party in favour of Brexit has huge majority despite the fact that more people voted for parties against that policy than in favour.
It isn't difficult to devise the bones of systems quite obviously fairer than the ones we have in the US and UK—any Year 9 Civics class could come up with a decent outline—and it is disgraceful that we haven't achieved this yet.