Generally speaking, students who are better prepared to write their papers use and cite their sources more effectively. The Poorvu Center describes several things instructors can do before giving out an assignment prompt to help Prevent Plagiarism. Although there is an ethical component to academic dishonesty, the overwhelming majority of plagiarists are working at the last minute on an assignment they feel is beyond their skill. Preliminary work towards a paper reduces both of these contributing factors.
Research shows that some conditions change the landscape for cheating, either by scaffolding students more effectively towards achievement, or by making the effort of plagiarizing greater than the reward. The Poorvu Center website also offers suggestions about two other practices that can reduce the risk of plagiarism: teaching directly about plagiarism and academic integrity, and revising assignments to reduce opportunities to plagiarize.