Endless details detract from the point; simple messages are more memorable.
Mock-up your poster first then ask which details you can dispense with, and dump them.
If you can omit it, omit it.
Edit all text to simplify verbiage, to reduce sentence complexity, and to delete details.
Go beyond merely identifying the categories like Results in section headings: state the message instead.
Forego the temptation to classify results by methods alone: a large heading that only states a method says that you care more about techniques than answers.