Metaphors are a good way to generate ideas. eg. How is a machine like a dictator? How is powerpoint like the Pacific Ocean? What is similar between a vacation and baking cookies?
Lateral thinking is random movement from one thought to another. A cake reminds you of sweet reminds you of diabetes reminds you of your doctor reminds you of your dentist reminds you of drilling reminds you of the oil prices reminds you of your bank balance and so on. Radial thinking is more systematic in that you come back to the original word or thought and build a web of words around the central idea.