I'd look into the Little Red Schoolhouse writing program-they may have an online version. They teach you to write effectively for your audience.

I agree with the suggestions to read more good writing and to practice writing more. Also, look up Grammar Girl.

NP. Agree with others, but also wanted to suggest that you get some feedback from someone who is a good writer, perhaps a communications colleague or friend who is a strong writer. Then remedy accordingly. For example,
Poor grammar? --> find fun ways to improve your grammar (not sure how)
Weak choices of words? --> increase your vocabulary
Ideas don't hang together or flow? --> work on structuring sentences and paragraphs.

All these have different remedies. You could get self help books for these various issues--and work on one thing at a time, bit by bit.

I consider myself a strong writer --it stemmed from my father imparting to me the importance of good writing, being a solid reader, and lots of jobs where I used this writing skill. Learning and teaching Latin was also an experience that made my grammar excellent. (However, I don't want to come across as smug; there are others with a real gift for writing which I lack, and I can always benefit from a excellent editor.) Learning Latin isn't everyone's cup of tea, but there could be other ways of improving grammar without it being a chore....
Anyways, good for you, OP!!

Write more, and read more.

Anonymous wrote:Read what those other people write and copy their style.

+1, read more. Actually, I would say you could read almost anything professionally published, including fiction, to get a better ear for how writing should flow.

I agree with PPs that you should take a class, too. However, you can start today by making sure your sentences are short: one to two thoughts per sentence. Get to the point and don't waste words. This makes for clearer writing and also helps you avoid some of the punctuation problems that people who "write like they talk" tend to make.

Read a lot.

Check out the course catalog for your local community college, you'll probably find some sort of basic Business Writing course.

Where are you? Do you want help with professional writing for the workplace? If so, MC has classes specifically for this. The Writers Center may too, but I think their classes focus more on literary writing.

The way to become a better write is to write more. Also, find a piece of writing you like and dissect it -- what made it so good?

Read what those other people write and copy their style.

For the past 15 years my job hasn't been one that required a lot of writing, besides emails and basic reports etc. I want to start going after different opportunities, but I know I need to become a better writer to even have a shot. I know the material better than most people at my level, but I just can't write as well as they can. Any tips on how I can get better? Are there classes I can take? I've been told that my writing sounds too much like the way I speak, and so it's not professional enough.