Which advice about reviews did you eventually ignore without fancy tools?

My current rule is simple: if it takes less than 9 minutes to prepare, I am much more likely to keep doing it.

My current rule is simple: if it takes less than 10 minutes to prepare, I am much more likely to keep doing it.

Would love to hear how other people handle this. I am especially curious about the version that works on a tired weekday, not just on an ideal Sunday.