Make a note of which source and what page you are referring to after each sentence you write. This does not have to be an official citation, just something to keep in mind when you are doing the final review of your work. Take a look back at the source and make sure you have made the sentence completely your own. If you haven't, make sure to insert quotation marks and cite the source properly. Be mindful of which sources you are using when drafting your paper.
Check your final draft on TurnItIn.Com before you turn it in. The website checks the paper for proper citations and checks it against other papers that students have turned in for the same class. Many institutions recommend the site and will give you an enrollment password in order to sign in with your school ID. Many teachers also use TurnItIn to check for plagiarism when they are grading papers, so, checking ahead of time will be beneficial for you and your grade.
Visit Viper Checker if you are prone to plagiarism. Viper Checker will allow you to check your work against plagiarism on a variety of levels in order to prevent even the slightest hint of copying. The program is free, but will only work on Windows- based systems. For supreme checking, the site will even have your work checked by a professor for you for a fee. However, this feature will take two to three days to complete, so, don't wait until the night before the paper is due to have it checked.
Check your work on Google to ensure that there is no plagiarism of Internet sources, including blogs, Internet articles, and company or government web sites. Cut and paste each sentence into Google and press "Search." Sentences that match yours or come up will automatically pop up in the search list, so you will be able to alter your work if necessary.