Grammar

For call-to-action words or phrases, use the infinitive.

Insert page element.	Page element should be inserted.
Register now.	You can register now.

Avoid modals.

This is supposed to work correctly.	This should work correctly.

Use the present tense.

Changes saved.	Changes have been saved.
Click Settings, and scroll down to the Downloads section.	On the Settings page you will find the Downloads section.

Use active voice in instructions.

Optimize your website.	Your website can be optimized.
Betty sent a message.	The message was sent by Betty.

Use singular or plural consistently.

Upload an image. Assign the image to your product.	Upload an image. Assign the images to your product.