I often use something close to 1.4, 1.6, and 1 for form elements

What do you define form elements?

Radios, checkboxes, buttons, input fields, stuff that I want to center vertically that are one line.

1.5 for dense text

Is that just the body type?

yeah, anything dense, paragraphs ect. headings i tend to leave at 1 and then add margins to match whatever fits the site

Choosing the optimal line length increases readability. → imperavi.com/books/ui-typog…