What organizational pattern is best to use when a piece of writing moves from one subject to another

When I move from topic to topic I try to plan it to where some of my last sentences lead up to the topic. Example: I was eating peanut brittle when my tooth fell out.
I hated the dentist. Going to the dentist has to be one of my worst experiences.
See how I made the last thing go with the other. That's what I would do!!