The last ideation technic I will share with you here is to use ideation cards that have creative prompts on them.

Basically, people receive a set of cards that have on them words, images, questions, or quotes that they can use as an inspiration to generate ideas. Here a few of these ideation card decks that exist:

Methodkit is a company that is focused solely on creating such kits, they have 40+ kits  on topics like: cities, trends, business models, etc.

Board of innovation created a set of cards to help you brainstorm. The set is composed of 52 cards that you can get as a free PDF that you'll print out yourself.

Triggers has created 12 set of cards pretty similar to those of Methodkit on topics like Planet-Centricity, Serendipity, Human-centricity, etc.