High standards about having low standards
There's a neat and fun way to fail at lowering your standards, and that's by having high standards about lowering your standards.
I believe this is a frequent failure method of lowering standards that goes unchecked because this requires a bit of meta thinking. But I could be wrong because I'm here.
Whatever. If your default behavior is having high standards, then you should expect that when applying perfectionism-defeating strategies. Having high standards about having low standards could go unnoticed but still derail you; you'll only notice that you've failed somewhere.
Because this is not rational, but default behavior, you should not expect to reason with this part of yourself. You won't find arguments about why you should care about having high standards. Instead, first comes the wrongness about failing an unsaid test, then comes all the rationalization.
Think about it, why does it feel wrong to lower your standards? If this were a simple first pass thing, then you could just say that you're lowering the standards here and it would all go well. But there's a reaction to the first pass, the unsaid test has been failed.
Maybe its possible to learn to lower your standards by thinking hard enough. I don't know its impossible, but it must be insanely hard. Maybe unthinking could lead here, I don't know if that's the case but maybe the many shapes of meditation and mindfulness could help here. I don't know if its inherent or correlative, but it certainly helps.
Its just so hard to give general solutions to perfectionism because the creed being held could be anything from
"You must not fail or everything is doomed"
or
"You must always be perfect or else everyone will call you out"
and all of these have different ways of being challenged. For instance the first one would be better challenged by safely failing in a controlled environment a la exposure therapy. While the second one could be challenged by both lowering standards to ok and observing reaction, or else by observing the little correlation between your actions and their social reaction (assuming double-bind or other abusive social dinamics and yada yada yada psychology)
Point being: Challenge the underlining assumption-belief. If its "perfection", then lowering standards holistically could work. If its "not failing", then failing holistically could work. I don't know. This is complicated. Just try to communicate with that part of yourself that they're wrong, its no biggie, and move on. Just mind the recursive hall of mirrors.