How Typography Affects Readership and Psychology

https://blog.kissmetrics.com/how-typography-affects-conversions/

This article gives a great breakdown of how font and typography can influence psychology on a practical level.

Some useful tips:

1. Variety is good, but don’t go overboard. Your copy should not be a display of your favorite typefaces. Simplicity is key.
2. To find the perfect typeface, study your niche and your audience. Does the typeface need to be formal or informal? Does it need to be larger? The answers can be found by performing simple market research, if necessary. But, if you are selling a product that will give people 20/20 vision, most likely your target audience will consist of people who are visually impaired in some form. So, in this case, using a simple large-size typeface is a no-brainer.
3. Choose a typeface that keeps your text both legible and readable. One way to do it is by picking a typeface that has large counters (the areas of the letters that are entirely or partially enclosed).
4. Do not capitalize every word or the first letter of every word in your copy. Ninety percent of the text that people read online is in lowercase.
5. When it comes to line length, don’t keep it too short because the need to constantly shift the eyes will make reading difficult. On the other hand, lines that are too long sometimes can make it difficult for readers to find the next line.
6. Make sure to optimize the letter spacing for the right density so that the words don’t look cramped and crowded, which can leave your reader frustrated and confused.