Typography: Letter Spacing and Line Height
The secret to choosing the right letter spacing and line height for your text when designing is to "eye ball it"
The simple practice of squnting your eyes and trying to read the text to see if it's legible enough to read.
You can also use letter spacing to create visual effects between texts using effects like kerning to reduce or increase the spacing between two letters.
This also applies to the line height of a text you're designing. Using the easy formula can help you figure out the right line height for any typeface you choose to work with.
Font Size X 1.4 = Line height