In Do your word counts measure up, Rosanne Bane describes her six-step process for writing. As much of it is also applicable to preaching, here’s a summary translated into preacher-ish:

Stage 1: First Insight
When looking for your next sermon, you’re asking, “What if, how about, why not…?”

This is when you should be reading widely to see what grabs your attention, completing an Interest Inventory, freewriting, clustering, mind mapping, and using other brainstorming methods [+ prayer].

Stage 2: Saturation
This is what we usually call exegesis:

In this research stage you seek as much information as you can about the topic, characters, setting, etc.

Stage 3: Incubation
As you’ve probably gathered too much information to make immediate sense of, let it sit, and go do something else as your subconscious mind sifts the data for associations and connections.

Patience is essential during Incubation; cracking the egg open early to see what’s happening inside only kills the chick…You might take a walk or a nap, freewrite questions and answers, try to explain the problem to someone else, cluster, brainstorm, doodle, or get your body busy.

Stage 4: Illumination
The flash of insight, breakthrough, the Eureka moment, whatever you call it, it’s he best feeling of the week, when everything starts fitting together. Jot down your theme, your dominant thought, your structure, etc.

Stage 5: Verification
This is where you start drafting your sermon, trying to make something tangible out of the illumination.

But don’t try to draft and revise at the same time. Letting your early drafts be imperfect approximations of what you’re trying to write is really the most effective approach.

Stage 6: Hibernation
For the preacher, this is probably Monday, when the primary task for the day is “to recharge your batteries and restore your creative energy.”

You need to do whatever renews your creative spirit. Look at beautiful images or art. Listen to beautiful music. Be in beautiful natural spaces. Garden, walk, sit by a lake or river, rest, wait. Give yourself time to just be; it’s the only way you can fill yourself up and have something to share again.

Come Tuesday, you start hearing some familiar questions again: “What if, why not, how about…”