Do you wash & block your swatches?
You know how patterns direct you to make a swatch before you begin your project? Do you actually do it? If you said "yes", here's another question for you: do you wash and block your swatch before you validate your gauge? I'm not a purist, and if you are doing something like a blanket, a scarf, or even some unstructured wearable like a poncho - then close-enough is good-enough when it comes to gauge. But if you are making a fitted wearable, then gauge is CRITICAL and it will make or break your project. Think about it for a minute: At some point you will need to wash whatever you make and washing the fabric and drying it is going to change...