An easy way of doing this is to read children's books, however stupid it may sound, they are designed for children learning the language and could be a good way of learning better sentence structures. Try to begin with the basics, full stops,capital letters,general word order; then progress onto more complex structure involving semi-colons, 'exotic' conjunctions. And I'm sure your writing will become more eloquent and sophisticated, although it really just requires a bit of practice.
I hope I could help.