Name the rule's purpose
If a guideline suggests placing a subject off centre, ask how that changes balance and attention. Make a centred version too. Compare actual effects instead of treating either arrangement as automatically superior.
Change with intention
Tilt a horizon, crop tightly, or accept blur only when it contributes to the picture. A departure becomes meaningful through the result, not through the fact that a rule has been ignored.
Use a contact sheet
View several variations together at a small size. Strong structures become easier to compare, and a favoured detail is less likely to hide a composition that does not hold together.