Where users meet your data.
Forms are where real people type unpredictable things. A good form is clear for humans and strict with what it accepts.
Clear
For People
A visible label on every field.
Plain error messages next to the field.
A confirmation when it's done.
Strict
For Safety
Validate in the browser and again on the server.
Only ask for what you need.
Required means genuinely required.
Protected
For The Bots
Limit how often one person can submit.
A hidden trap field or a challenge.
Watch for sudden floods.
Validate twice: browser for kindness, server for safety.