Of course my advice to marketing folks who want to write their own ads should be, Don't—use a pro writer like me. (We're really good, and we've got mouths to feed.)
But when you want or need to write ads or promotional text yourself, here are some tips that will help you come up with a message and concept that work.
To keep this simple, we'll use Joe the carpenter as our metaphor. I know carpentry doesn't have a lot in common with major business corporations. But the principles of how to approach promotional writing are identical, whatever the subject matter.
So what have we got (with no frills)?
Joe the carpenter is really good at making things out of wood.
We'll get a lot more done a lot faster if we forget that and instead focus on what we want to achieve.
Joe wants to increase and consolidate his business as a carpenter specializing in woodwork for people's homes in this area.
Now we need to figure out the best way for him to do this. In the advertising world, this would be handled by the planners/account team etc.—not the copywriter.