Diagram all the things!
A shorthand for designing UI flows
I like to communicate user flows using the format described in this article. I prefer a text-only format because it's quick to edit and explore various options without getting caught up in the visual execution. Once the flow is final, adding in thumbnails is fine, but it's extra effort. I've found that the text-only flow accompanied with UI page designs and a convo with engineering is enough and saves me from making lots of little thumbnails.
5 questions to ask before you create a customer journey map
What You're Getting Wrong About Customer Journeys
A thoughtful framing of customer journeys on a 2x2 matrix of level of effort & predictability
Inclusive design principles and activities by Microsoft
Emotions Wheel | PeopleStorming
Helpful for articulating more nuanced customer feelings