One of the difficulties a writer faces is reviewing their work in an attempt to locate all errors. There are generally two forces that work against a writer who attempts to ensure their work is error-free.
1. Being too close to the work you have difficulty concentrating on the writing.
2. You know what you want to say so it is possible you read over mistakes simply because your mind only sees your impression of the article.
In order to be effective in proofreading your own material you have to work hard at reading every word
Refuse to speed through simply because you know what the writing says.
Consider each word, then each phrase and then the context of the thought.
Does the article flow or are there phrases that bog it down?
Check punctuation and grammar.
Look at the headline and make sure it is correct.
Do the above all over again.
Most often the best personal proofing requires multiple readings and ongoing edits. The key to the entire process is discipline personal and professional discipline.
Check and recheck the facts in your story and when possible allow another set of eyes to proofread your...