It is very important that you keep a record of your various drafts, so that you can see the evolution of your writing. On the first draft, write “First Draft”, and the date; on the second draft, write “Second Draft”, and the date, and so on. Either save your draft into your computer, or (better still, I think), print it out, so that you can easily examine it. Again, I think that you should print out what you have written, double-spaced, so that you can write with the “correcting pen” all over it, and edit, and re-edit what you have first written. There is nothing wrong or shameful with a page covered in pen-corrections in another colored ink. Remember, “Writing is a process”, and you have to make that process happen.
You should revise the text of your article at least two times, (a) for structure and content, and (b) for grammar and spelling. That is, if you have a “peer reviewer” (perhaps a classmate, or a colleague) helping you, that person can look at your article two times. First, this friend edits your work, according to problems of structure, logic, and content; then, you correct it. Second, this person edits your work again, this time in terms of grammar and spelling; then, you correct it, and give it to the teacher. If you have two friends working together, or one after the other, so much the better. They should know that it is alright to “directly edit” your work; to write all over your paper is not going to make you “lose your face”! This writing and editing process should be spread out over most of the week, in order to get a better “product”. Use the blackboard freely, so as to improve your sentences. Have two or even three friends to give “constructive criticism” of your text; they should deal with the facts as they appear, and not be hampered and slowed down by considerations of “saving face / losing face”.
Finally, you should use the computer to write bold-face, underlining, italics, and spacing, so as to make the plan and the article text easy to read. I hope you will enjoy writing expository articles, using the 7 x 7 structure, along with the six sentence types!