Don't do monolingual RTK, it's stupid and tedious. After you've achieved basic fluency, do production TSCs instead.
RTK is a huge waste of time if you do it monolingually because then you have to reinvent it. You have to rename all the components using Japanese names, and you have to come up with your own mnemonic stories in Japanese.
RTK is focused on learning to write kanji in isolation, but when we write Japanese, we always write words. So if you do production TSCs instead, all you have to do is find a sentence you like, occlude a word in it and practice writing the hidden word.
If you're fluent in Japanese, you probably won't need stories to memorize how to write most words because you've already seen these kanji so many times, you already have a vague picture of them in your head. If you just look at a word once, draw it on a piece of paper and pay attention to the strokes, then you'll remember it.