A good form is one you do not remember completing. This makes form design almost impossible to praise, because the evidence of success is an absence.
The failures are memorable
A field that clears when you make a mistake. A label that vanishes the moment you type. An error that says "invalid input" without saying which input, or why. Every one of these is a decision someone made, usually to save implementation effort, and every one transfers that effort to a stranger.
The test
Ask someone to complete it while narrating. Count how often they stop to work out what is wanted. That number, not an opinion about the layout, is the design.