The standard contact form in the Shopify theme "Dawn" is a great way to improve customer UX by tweaking it a bit. By displaying a confirmation message before submission and displaying a separate page after submission is complete, you can impress upon customers that their inquiry is being handled appropriately.
How to implement "Submission confirmation" and "Transition to a page after submission" in the contact form of the theme "Dawn"

[How to set it up] Add a "Custom Liquid" section to the page template "contact" and insert the code

