The first step in preparing a message is to prayerfully determine the preaching text. It’s important to make sure you are studying a complete unit of thought – a full paragraph, a full narrative, a full poem, a full wisdom saying, etc. But then be sure you have peripheral vision.
Make sure you continue to look around and be aware of the context of the passage. Too easily we get blinkered by section headings and forget to see what has preceded and what flows out from the text that we are studying. Everything needs to be seen in context. If you happen to be in a place biblically where context isn’t helpful, you’re in one of only a few places.
We need peripheral vision as we study the text, or we so easily may miss what is right there.
Biblical Preaching 
Peter,
I have always enjoyed reading devotionals written by pastors from “back in the day” and, since I have started preaching in the last few years, I have difficulty reading them for the very reason that you mention. The devotional writer (no names will be mentioned since the names are very recognizable) will take a verse and write a devotional on that text. It may be well written and thought out but when I look at the larger context, the devotion doesn’t make sense. I doubt that the Biblical writer would agree with the devotional writer. Similar to a journalist taking a quote and then writing for his purpose. Peripheral vision is a must.
Mark Webb
I agree. It frustrates me to no end. It also frustrates me that most children’s programs in churches are now just teaching moral lessons with occasional scripture to back it up instead of teaching what the scripture is saying.