As far as I understand the world championships in mnemonics all get won via memory places that use spatial memory. At my present project of making phonemes learnable I specifically show the charts of phonemes along with my minimal pairs to give the user an orientation.

Venn diagrams are a nifty tool for giving knowledge a structure. I use them in Anki to distinguish essential, semiessential and nonessential amino acids. I however haven't yet programmed automatic Venn diagram creation.

The supermemo principles by Wozniak suggest against learning multiple similar items at the same time. If you have a deck about British monarch there nothing wrong with spreading it out at 1 card per day.

As far as automatic remembering of detail about people goes, it often works via narratives. Narratives are difficult to display via Anki.

I personally had a heard times following along the who's who of Game of Thrones on the other hand someone on LW has used the example of remembering facts about Game of Throne as a way to illustrate how easy it is to remember facts about certain subjects. .