It’s a classic conundrum for any graphic designer: picking two (or more) typefaces that set each other off, don’t fight the eye for attention, and harmonise without becoming homogenous and dull. The age-old rule goes as follows: concord or contrast, but don’t conflict.
The easiest way to achieve ‘concord’ is by using different fonts within the same overarching typeface family. Find a so-called ‘superfamily’ and you’ll have a ready-made range of weights, styles and classifications that are specifically designed to work together.
A good superfamily will include serif and a sans serif version of the same typeface: famous examples include Lucida/Lucida Sans and Meta/Meta Sans.