Neologists kind of use the last writing prompt with prefixes, affixes, and roots. Take a root word from here, an affix or two from there, and voíla, you can build a new word. It’s like a puzzle that can be combined into hundreds, thousands of different ways. And the best part? You usually don’t have to think about it. It just happens.
Now, getting it accepted into normal speech (or, say, the dictionary) is a whole other story.