1. Go for Readability
When it comes to readability, typefaces should be easy to scan at a distance and provide a clear distinction between letterforms. Fonts should be large enough and contain enough space between lines so that letters don't look cramped or tight, but not so much that users have to think about what the words say.
A highly readable typeface also has a clear distinction between upper- and lowercase letters, such that the x-height (height of lowercase letters) is shorter than its uppercase counterparts.
One of the best ways to think about readability is the I/l/1 test. Put an uppercase “I," lowercase “l" and the number "1" side-by-side-by-side. Can you discern the different characters?
Fonts to try: Roboto (sans serif), Georgia (serif) or Lobster (decorative)
2. Look for Uniform Stroke Widths
Alternating thick and thin strokes in the same letters might look more interesting but can be a little tougher on the eyes. (Save those for headlines or headers.)
Fonts to try: Ubuntu (sans serif), Merriweather (serif) or Komika Axis (decorative)
3. Don't Go Too Thin (or Thick)
Thin letterforms, for example, only really work with dark type on a light background and can look a little strange from the backlighting of a computer or phone screen.
Extra wide or thick letterforms can weigh down a design and force the copy to include a lot of line breaks, disrupting reader flow.
Opt for something in the middle. You'll know these typefaces because they will often contain a cue such as “regular" or “medium" in the name. You'll most likely want to avoid “ultra-condensed," “ultra light" and “black" options.
Fonts to try: Lato (sans serif), Alike (serif) or Berkshire Swash (decorative)
4. Pick One Bold and One Light Option
Fonts to try: Raleway (light sans serif), Alfa Slab One (bold serif) or UglaQua (decorative)
5. Use a Sans Serif and Something Else
However, the downside is a sans serif in itself can be a little boring. Pair it with a display or novelty option that fits your brand style a little more. (It will look interesting when paired with a funkier option or stand out more when paired with a heavy typeface.)
There's no rule that you have to use all sans serifs or serifs; you really should branch out and try to pair typefaces of different styles. The trick to making sure they match is to look for letterforms with a similar shape. Use a lowercase “o" as a starting point. What does the inside of the letter look like? Is it perfectly round or more oval? Straight up and down or with a slant? Pair typefaces of different styles, but that have a similar “o" shape for the best results.
Fonts to try: Seaside Resort (decorative) and PT Sans (sans serif) or Patua One (serif) and Molengo (sans serif)
Conclusion
When it doubt, take a look through the theme gallery to see which fonts are paired—these templates are made so that all the elements match. Get some inspiration and jump-start your typography project today.