Domain Experts / Subject Matter Experts / Industry Experts have invaluable knowledge that you can (and should) apply during your UX process. Domain expert involvement is not an alternative to UX research, and a domain expert is certainly neither a “user expert” nor a designer.
Interviews
Domain Expert Interview — UX Knowledge Base Sketches
Microinteractions play a large role in our digital lives, even if we don’t always notice them. From the time your phone’s alarm wakes you in the morning to liking your friends’ posts on Facebook to the notifications about new emails and Instagram messages—we encounter microinteractions all day.
Jakob Nielsen's 10 general principles for interaction design. They are called "heuristics" because they are broad rules of thumb and not specific usability guidelines.
Usability
10 Usability Heuristics for User Interface Design
Knowledge
100 Tools to Launch & Grow Your Start-up Without Web Weveloper, Graphic Designer and (almost) Without Money