First Rule of Design
The first rule of medicine, and part of the Hippocratic Oath, isprimum non nocere, or “first, do no harm.” There’s a strong corollary in design. In a redesign of a product, an update, or design iteration, it should always follow what I think is the first rule of design: “first, don’t make it worse.”
In essence, don’t regress in the pursuit of progress. Iteration doesn’t have to be mind-blowing, it just can’t be worse. Regress in design is the worst possible experience.