Wow – thank you everyone for your responses. I’m blown away by the depth of support!
I get the feeling you guys welcome (or at least benevolently tolerate) alternative thinking, so here goes…
In saying the below I’m going to assume that we can all agree that kanji readings are abstract until applied. In other words, knowing the three most common readings for 大 doesn’t actually achieve anything until you start learning associated vocabulary. And learning said readings at the same time, in the abstract and using mnemonics, can be something of a nightmare (especially when you run into issues I’ve been having in terms of mnemonics overlapping with one another).
So, what if you learned kanji and vocabulary independently of each other in a process that encourages readings to be learned implicitly and only when needed?
Let’s say you work on learning the most popular kanji meanings (i.e., not readings), using associated radicals and mnemonics as necessary. You also start learning the most common words – by which I mean you recall the English meaning from the Japanese hiragana (not the kanji) or vice versa, depending upon personal preference. So, you’re learning to read kanji symbols, and to speak (or understand spoken) vocabulary, but you are not directly learning to read the meaning of vocabulary written using kanji (i.e., without furigana). In other words, you’re not thinking consciously about kanji readings.
I believe that by doing the above, in time you might implicitly learn the readings for many kanji without explicitly learning them. For example, if you knew that “big” in Japanese was たい, and “great” was たいした, you’d probably be able to guess that the ‘kanji vocab’ 大した meant “great” without having to actually learn the reading, per se. And if there were any gaps, you could fill them in as necessary (i.e., if you spotted a kanji vocab word that you didn’t recognise but ‘should’, on the basis that you know the kanji within and the vocab word itself).
I know one argument against the above will be that you don’t get the ‘help’ from learning similar concepts at the same time, but I personally consider that a double-edged sword, in terms of mnemonics getting mixed up. I also believe that your ability to learn any given concept should ideally stand up in isolation, without needing ‘help’ from other associated concepts. Finally, this approach would cut out the ‘arbitrary’ learning of readings, only requiring you to directly learn them when it’s proven you haven’t absorbed them indirectly through your studies.
I hope that makes sense!