The Checking Process
This step is often overlooked if you haven't factored in enough time to do it before your deadline looms.
It is as important, if not more important, than all the other steps in the process.
If you publish something that contains errors, your readers will spot those errors and make a judgement about you and your business and that judgement will usually be negative.
Make sure you have enough time in the process for someone other than the author to check what has been written. Engage an Independent Pair of Eyes, such as an Editor/Proofreader to make sure your work is accurate, it looks professional and it's free from errors.