Go to this website

http://voanews.com/specialenglish

Select an article that looks like an academic one.

Read the article twice, make sure you understand them all. If in doubt of any vocab, consult online dictionary.

Then copy the article by typing it out sentence by sentence until the end of the article.

Then read the article out sentence by sentence, trying to analyze each sentence, at least trying to identify subject verb object and all the modifiers.

Do at least 3 articles everyday.

If you are weak in any skill, the only way is to practice, practice and practice. The best practice is to copy the master. VOA articles are written by masters of the English language.