Usually most of the fields are necessary,So only mark the optional ones.
Keep it simple and try to Synthesize.
Autocomplete options reduce the time a user takes to fill a form.The lower the time ,the higher the conversion rate.
Call to actions should state the Intention.
Show where the error is and provide the reason. Don’t make the user wonder where they made a mistake.
Bullet point on the password requirements creates a much friendly and seamless onboarding experience.
Microinteractions can save your space,time and combine some of the basic rules discussed previously.