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.