You make have heard a joke like this before:
A man broke his hand and went to see an orthopedic surgeon. He says, "Doctor, you have to help me. I've been to three other doctors already who couldn't help me. I need to know: will I be able to play the violin when my hand heals." The doctor takes some x-rays and says, "Well, your hand is definitely broken. I'll have to do surgery and you'll be in a cast for at least 6 weeks. But, yes, you'll be able to play the violin when I'm done."
Six weeks later, the man returns to have the cast removed. He says, "Doctor, I'm so excited to have this cast off." The doctor takes off the cast, and the man asks "So now I can play the violin?" The doctor says, "Everything looks perfect. Yes, you will be be able to play the violin."
The next day, the man returns, carrying a violin. He is angry. The doctor asks, "What's wrong?". The man says, "You told me I'd be able to play the violin. I've been practicing all night. Listen to this." He begins to play. The doctor looks horrified. The doctor says, "Oh my God. You sound terrible. I don't know what happened." The doctor orders more x-rays and scans, and they don't show any problems. The doctor says, "The bones healed perfectly. There's no nerve damage. The surgery went perfectly. I don't understand why you sound so terrible. Tell me everything that happened."
The man says, "Well, I always wanted to play the violin. I tired to play, but my hand couldn't do it. So I broke my hand . . . ."
How to do improve your writing? The same way you improve anything: Practice. Practice. Practice. But that's only part of it. Like the man in the joke, practice alone isn't enough if you don't have the basic skills to build on and improve through practice.
The Nature of Writing is a great free and open resource for developing your writing. It offers easy to understand explanations of elements of effective writing. And, it has quizzes that give you immediate feedback. Try out a few now:
Comma Splices and Fused Sentences