Be careful of your spelling, grammar, word choices, and style. Use tools, like dictionary and grammar checkers, to help you on that. Proofread your work at least three times before submission.
It is a temptation to copy a good paragraph, or a wonderful sentence from books or papers. But that is plagiary, which is absolutely forbidden. Rephrase it in your own words.
Do not cite the source indirectly. Be sure that you had read all the citations.