For me, I've found that having audio for every card is invaluable. Preferably audio from the source where you first encountered the word (for me that's mostly Youtube or Netflix). I'm working on a chrome extension to make this easier. Not only does it make it much easier to remember the word (by a pretty significant margin), but it has done wonders for my pronunciation as well.
I've written a little bit about my process here[0], but it's changed a little since I wrote that.
[0] https://mochi.cards/blog/using-spaced-repetition-to-learn-a-...
I heavily rely on mnemonics and I have a field for them, thus for the German word "vertrauen", which stands for "to trust", I have the following mnemonic: ”I trust Ver to heal my wounds”. Ver is a friend doctor of mine.
For Japanese it helps me to have also mnemonics for kanji sounds(ka - cat, ho - hole), then make stories based on them.
The one thing I was missing from most SRS apps was the ability to create note cards, not necessarily in the review schedule, and link them with my cards. There are some concepts like grammar that fit the "note" format, but don't necessarily work as a flashcard. Something like a Zettelkasten + Anki, but with nicer interface like Notion.
So I built an app[0] that does just that with markdown. If that sounds interesting to you, or you've been frustrated with Anki, take look and let me know what you think.
[0] https://mochi.cards/