If you'd like to be horrified, Alpha Phoenix shows how to make election maps that don't look like they've been gerrymandered, and might be hard to spot what is wrong with them!
I was going to post that video. First past the post is broken. Technology has far outpaced the idea when a YouTuber can draw harmless looking maps to not only decide elections but also decide how sensitive the election is to voters changing their minds on specific issues.
I always think of this infographic illustrating an easy to understand version of districting/gerrymandering. It's obviously leaving out the real life complexities and difficulties, but it gets the idea across.