Working a job outside of the church has many benefits, but probably one of the most under-rated is the potential for developing illustrations for sermons and devotionals. Rich real-life applications can be drawn from almost any job, and these touch people in a way that illustrations from a book or from the internet simply do not. Carry a small notebook or a computer tablet to jot down notes for things you might use later. If you can, develop a file of illustrations and stories with subject categories so you can find them easily. Some guidelines may be in order, though.
First, look for stories and illustrations that touch as many people and circumstances as possible. When you are preaching, writing or delivering a devotional to the men;s breakfast you don;t know who might be in the audience or what circumstances they may have in their own lives. John Wesley would hone his sermons to be understandable to the lowest common denominator, and we would be wise to do the same. Unless you are delivering an illustration to a particular audience, such as the time I delivered a devotion to a group of ministers, you should appeal to the widest audience possible.
Second, be careful to generalize your story to save embarrassment to other people unless you have obtained their permission beforehand. One of the most frequent areas I have found to be at fault here is the story is about your own family. Being transparent is admirable, but if you tell a story about your spouse in an unflattering or embarrassing manner you may end up sleeping on the couch! Children are perhaps even more susceptible to feeling humiliated by a story than your spouse. This is one area I find myself having to be conscious of when I speak (and I often fail!).
Third, be aware that drawing your stories from real life may open you up to other challenges. Some of these might even be serious enough to warrant legal assistance. If you tell a story involving your workplace improperly it may cause your employer to consider workplace discipline up to and including termination. If you are talking about your work, be sure to avoid anything that could put your employer in a bad light or be a violation of workplace confidentiality.
With all of that said, you can feel blessed as a bivocational pastor in knowing you have expanded opportunities for developing real life, touching and impactful illustrations.