A sure way to improve your writing is to re-read and re-write a few times. Leave it for a day or so and come back to it - there will always be improvements to be made.
In your final draft aim for:
Clarity - make what you are trying to say crystal clear. For example:"Anne met her mother at six o'clock. She had been working all day." What is wrong with this? Who had been working all day?
Or,"The natives looked friendly but they didn't offer them any food."Who didn't offer any food and who didn't get any?
Accuracy - "Standing on the bridge the National Theatre is an impressive sight."
WHAT IS WRONG WITH THIS? Imagine a foreign visitor reading that and thinking, "Wow, I must go and see that theatre on a bridge."
Or,"At the age of three her father took her to Canada." Advanced, wasn't he, for a three year old?
Proper Use of Words - Don't take a chance on words that you are not sure of. Check the dictionary.For example: When do you use 'infer' and 'imply'?
Or,: 'principle' and 'principal', or 'after' and 'afterwards' or 'borrow' and 'lend'. If you are not sure CHECK.
Be Careful With Adjectives - Adjectives should INFORM or describe but never make the reader stop with a question. 'long' doesn't tell the reader how long. If something or someone is 'short' how short is short?
Brevity - Doesn't neccessarily mean writing short pieces, nor does it mean cutting and cutting until there is hardly anything left by the time you have finished - all you will be left with is a skeleton - you need some flesh to make it interesting.
Brevity means telling in 200 words a story you've first written in 400 - leaving out nothing that matters. An aid to brevity is trying to make sure your writing sticks firmly to the point. It can be surprising to see just how many words can be cut without changing the essence of the story.
Short words - In the English language there are nearly always two or three words with closely similar meanings. Choose the shortest one. Use a thesaurus. Examples: Obtained (got); Employ (hire); deceased (dead); Go and see (visit); be on the lookout (watch); at this moment in time (now).
Avoid Reptition - i.e. The fireman's hose doused the flames and put out the fire. Either say: 'Doused the flames" OR "put out the fire." - either one is superfluous.)
Learn How To Editor Your Own Work - The dictionary says the word 'edit' means 'prepare for publication'. To professional writers this means rewriting and rewriting. A first draft is almost always overwritten - rewriting gives you the opportunity to clean up carelessly repeated words and clumsy sentences, get rid of cliches, etc. It helps you spot flaws.("Anyone can write, only writers can re-write.")
Develop Your Own Journalistic Style