I thought the standard advice was that, while it would be better if your natural cadence was 90, still, if it isn't, then it's better not to try to mess with it. After all, your body has a lot of experience running as works best for it.
Actually this book argues the opposite, which is that your body has generally been conditioned to run badly by your posture-unfriendly daily activities like sitting at a computer, so you need to retrain it to run 'naturally', which here includes cadence.
But I'm with you, that seems one step too far (at least a radical change does.) Luckily I feel that being taller and leaning forward less naturally increases my cadence a bit.
Doing running drills might be a good middle ground. I've also heard it said that trying to revolutionise your form can be a bad idea - but drills can expand your range of motion, and you can then trust your body to deploy that better range of motion more or less naturally.
I am no expert but did notice when I spent a few days in Ethiopia that runners there seemed to do a lot of drills, and they seem to do OK as a running nation.