When I first started I disregarded mnemonics entirely. But I kept hearing people who were very advanced in Japanese talk about the usefulness of mnemonics for remembering. Both people who use WaniKani and those who didn’t all seemed to agree they were important. So, I started implementing them into my own study.
I can say it has certainly helped me recall new kanji more easily. And sometimes when I come a across an old review and I feel the panic of realizing I had forgotten the kanji the mnemonic will suddenly come back to me and I remember the meaning and sound again.
One thing I will say though is that you should create your own mnemonics. Personally, I find many of the examples WaniKani gives to be ridiculous and no easier to remember then the kanji itself. There are likely connections and stories you can make for yourself which are most easy for you to remember. I think this is true for each individual.
One example I can think of is for the kanji “sell” 売. The On-yomi for this kanji is “bai” ばい. WaniKani gives some weird mnemonic I didn’t bother to remember. It seems so obvious to me that the easiest way to remember this is with “buy/sell”, two English words with opposite meanings. With almost every kanji there is likely a more intuitive way for you to remember personally. Another example is that I have a friend named Kyu, pronounced exactly like きゅう. So I associate my friend with any kanji that has this pronunciation.
