Choosing the wrong chart type is like answering a different question than what was asked. An Hourly Chart captures the energy of the present moment; an Event Chart captures the energy embedded in a past occurrence; a Natal Chart captures the energy of a person's birth. Each serves a different purpose, and confusing them will produce misleading readings. Knowing which chart to cast is the first decision you make in any divination session.
This is your default chart for divination. When someone asks a question, you construct the QMDJ chart for the current Shi Chen (two-hour period) at the moment of inquiry. This is what you will use for the vast majority of your readings.