You use any writing tools at your disposal to accomplish that end. One of the most common ways of explaining a process is to divide it into steps, phases, periods, stages. These are essentially time segments groupings of closely related events or actions. However, most process discussions aren't much without explanations of the causes and effects operating behind them. For example, it's not terribly exciting to read that when tornadoes form, it gets cloudy, windy and rainy and the twister touches down here and there, wrecking things.
Definitions Explain the meaning of any technical terms used in the discussion.
Comparisons Compare the process, any of its phases or outcomes, to something similar or something familiar to help readers understand. Examples Provide examples of the process you are explaining. For example, in a discussion of tornadoes, examples of tornadoes in history can help. Here are a few suggestions on format as they relate specifically to process discussions. If you write an extended process discussion and structure it by steps or phases, in other words, time segments, then the subheadings can be related to those steps or phases, as illustrated in the schematic view of process discussions .