Buttons

-Should always contain actions written clearly and concisely
-Capitalize every word, including articles
-Within text/instructions, capitalize and bold navigation and button labels as they appear in the app or website (Tap the Submit button)
-Make button text as brief as possible; avoid sentence-length text

Checkboxes

-Use when multiple choices may be selected
-Use sentence case

Radio Buttons

-Use when only one option may be selected
-Use sentence case

Forms

-Capitalize every word of form titles
-Use sentence case for form fields
-Only request information that is needed and will be used

Headings

-Capitalize every word of headings (except articles [a, an, the] and conjunctions [and, but, for, nor, or, yet, so])
-Aim to keep heading length fairly short; do not exceed one line of text if possible
-Use sentence case for subheadings

Images

-Give every image descriptive alt text 

Links

-Underline links

Lists

Bulleted Lists

-Use sentence case for each item and strive to use complete sentences unless the list items are short descriptions or make sense to appear as phrases
-Do not put a period at the end of a bulleted item unless there is more than one sentence in the bullet

Numbered Lists

-Only use for step-by-step instructions
-Separate steps into logical chunks, with no more than two related actions per step
-Use sentence case for each item and strive to use complete sentences

Menu Items

-Use sentence case

Navigation

-Capitalize every word in main navigation (except articles [a, an, the] and conjunctions [and, but, for, nor, or, yet, so])
-Use sentence case for sub-navigation

Paragraph Text

-Aim for 45-85 characters per line
-Try to keep length at <16 lines