Asynchronous JavaScript techniques offer various approaches to handling asynchronous tasks in JavaScript. Callbacks provide a straightforward way to react to events, but they introduce tight coupling between event emitter and listener code. Promises have advantages over callbacks, such as loose coupling and the ability to chain multiple asynchronous actions. The async/await keywords improve JavaScript's asynchronous programming capabilities by providing a more readable syntax for handling promises. RxJS Observables offer loose coupling, repeatability, and compatibility with promises, making them suitable for complex scenarios like interacting with WebSockets or performing REST API calls. A decision tree can help choose the right technique based on specific use cases, such as repeatability, emission frequency, and listener requirements. By understanding the strengths and weaknesses of each approach, developers can select the most suitable asynchronous tool for their project.