There are usually a couple of marks in the grading scheme for good grammar and punctuation, so a little overview at the end of your writing process should give you a boost and may push you over the grade line.
Check your spelling and grammar
Set your spell and grammar check to the right one (English UK if you are writing in English for Malaysian teachers and students). Then go through your document and accept or reject each item.
List and fix your top most commonly made mistakes
For example grey and gray or live and leave or meet and meat or here and hear. These mistakes are not normally picked up by a regular spell check, so do look through the document using Edit, Find and Replace commands.
Print your paper
It is amazing how differently things look in print and how much easier it is to spot mistakes. Just whip through it and mark up problems with a marker pen. Then go back and fix the problem.
Read your paper out loud
It depends on how you process information, but some people find that they hear their mistakes better than they read them. This may or may not work for you, but it is worth having a go. For best results, print your paper, pick up a marker pen, then stand up and orate. Mark the sentences that need fixing.
Swap papers with someone else
Once you have written something, it becomes quite hard to see it impartially. Get a fresh set of eyes to give your work of art a last polishing – and as it is quite hard work, see if you can swap the service with a classmate.