I mentioned last week in the Pastors Today e-newsletter that I have recently completed studying a book called Made to Stick by brothers Dan and Chip Heath.
One element that I've been applying is their recommendation to include "specific details" when telling a story. They say that it helps people to visualize the situation you are describing and makes the story more "credible" or believable.
For instance, this past Sunday our worship service used the sports theme "Game Day Central" since we were kicking off our Vacation Bible School. I was sharing a personal illustration during my sermon about a football player that lived next door to us. As I told the story, I purposefully used concrete details in my story.
Instead of saying, "Rocky drove up into his driveway," I said, "Rocky drove up in his Blue 1973 Fastback Mustang." Instead of merely saying he was a football player I added the following details, "Rocky is 6 foot 4 inches and 245 pounds and has red hair and freckles." (For my International pastors, that's 193 centimeters and 111 Kilograms.)
You can imagine how those details helped the listeners visualize what I was describing and also made my story more believable. I encourage you to try this in your next sermon.