5 Mistakes That Weaken Your Writing

I'll be the first to say that being a successful freelance writer requires more marketing and business savvy than writing skill. Writing beautiful, flowing prose won't make you much money unless you know how to market yourself,negotiate fee structuresand contracts, and keep your editors happy. That's why this blog usually focuses on business strategies for freelancers.

However, avoiding common writer's pitfalls certainly helps. Here are several ways in which you may be weakening your writing.

1. Incorrect word usage.
   I see this all the time in blog posts: the writer uses affect when she means effect or whether when she means weather. It's even worse when someone mixes up words that don't sound the same but share a few common letters. Guest blogger Laurie Pawlik-Kienlen wrote a piece oncommonly misused words and phrases. Grammar Girl is another good resource for grammar and usage questions.
2. Poor use of quotes.
   I used to insert lots of quotes into my articles even when it would be simpler to paraphrase the person's insights. But too many quotes can interrupt the flow of your article, so I've since learned to focus on quotes that add color. Usually the writer should summarize background material instead of directly quoting a source for every statement (though you canuse phrases like "According to Jane Smith" or "Smith says that ..." to attribute this background information). Michelle Rafter offers more insights on the correct use of quotes.
3. Lack of sentence variety.
   Are you using the same tired structure for every single sentence? Do you overwhelm the reader with too many long, detailed sentences in a row? Do you see the point I'm trying to make by using a series of rhetorical questions? I bet you do! Now I'm changing things up to show you how much more interesting that is. Although starting a sentence with a dependent clause can sound intelligent, this syntax shouldn't be used too often or it can sound repetitive. Vary your sentence structure. Throw in a short, punchy sentence to break up a series of longer ones. Use rhetorical questions sparingly.
4. Passive voice. 
   I don't agree with everything that English teachers say ("Never use sentence fragments!" "Never end a sentence with a preposition!"), but in most cases, passive voice does complicate and weaken your writing. Why say "this blog was updated by Susan" when you could say "Susan updated her blog"? Grammar Girl offers even more information on thepassive voice.
5. Over-writing. 
   Lively language can keep the reader interested, but over-using alliteration or metaphor or other devices can fall as flat as a day-old pancake at a roadside diner. If a metaphor makes sense and supports the point you're trying to make, go for it! But if you're including a clever aside or an impressive SAT word to show off, that usually detracts from your writing and obscures your message. Ditto on the adverbs and adjectives. Often you can find a more interesting verb or noun to eliminate the need for modifiers.

http://www.urbanmusewriter.com/2010/08/5-mistakes-that-weaken-your-writing.html