Interfaces with differential pairs during PCB Design
Generally, differential pairs are used in high-frequency data lines, which are most prominent in devices used in sophisticated applications (memory buses, digital video, etc). And sophisticated devices tend to have associated literature to assist in the design where they describe which traces need to be routed as differential pairs.

What that means is you don't really need to memorize which kinds of devices do and don't require the special routing technique. You DO however need to always read the datasheets, design guides, and reference designs. 

That's how the pros do it.