Miss Steaks, I mean mistakes happen in writing. They happen all the time. The first lesson I learned in proofreading class - yes, I took an entire semester of proofreading - is that you are in love with your own work. That means you won't see your mistakes. You know what the words should say. You glide over them.
Some mistakes are more earth shattering than others, for instance, a pubic auction notice instead of a public auction notice. The picture I've posted here to the left cost someone a headache. First all the calls that must have come into the department of public works complaining about the sign. Next the dressing down someone may have gotten about the mistake. Then there is the ribbing about the ludicrous idea of trying to stop a woman from doing anything she has her mind set too. And finally, the actual financial cost of the new sign and the removal and replacement of the new sign. It has been fixed.
How do you safeguard against mistakes? Assume that they are going to happen and find a few readers. This is called a fresh eye review. Someone who is not familiar with the subject matter - even a sign - who can look at your work and catch those pesky problems.
I've learned a few important lessons about proofreading since I started Home Row Editorial. A good proofreader can be taught the mechanics, methods, and proofreading marks. I'm that type of proofer. A great proofreader instinctively knows how to do it. Those are the people I hire.
Save a headache or two, and potentially some money, and find a good proofreader when it truly matters.