UX design is the process of brainstorming solutions to improve user experiences by addressing the user’s needs, wants and pain points.
https://www.justinmind.com/ux-design/ideation-techniques

Brainstorming
This is an informal way to combine problem solving and lateral thinking.

mindmapping
this is a concise and organised summary of your ideas begining witha main idea and working your way out with side notes

Sketching and Crazy 8s