A pattern is helpful until the material in front of you asks for an adjustment.

Templates carry accumulated experience, which is why they work most of the time and fail in a particular way. The pattern was made for the average case, and the cloth, the person or the situation actually in front of you has a feature nobody anticipated. Following it past that point produces something technically correct and quietly wrong. Judgement is the part a pattern cannot contain.

When the guidance and the evidence disagree, look harder at the evidence. Note what made you deviate so it can be explained later. Rules deserve respect rather than obedience.