Sometimes, we refer to online references and change a few things, which again leads to plagiarism. But, there is always an opportunity to eliminate plagiarism issues. New students tend to have the temptation to copy others work and use it as their own. Hence, below are some good practices that you should adopt to avoid plagiarism issues.
Paraphrase - So you have found information that is perfect for your essay paper. Read it and frame it into your own words. Make sure that you do not copy more than two words in a row from the text that you gonna use. If you do use more than 2 words together, you will have to use quotation marks.
Cite - Citing is one of the best ways to avoid plagiarism. Follow the document referencing guidelines (i.e. APA, MLA, Chicago, etc.) used by your school. Citing is really that simple. Improper citing can constitute plagiarism.
Quoting - When quoting from a source, use the quote exactly the way it appears. Misquoting can cause a lot confusion. Most markers frown on “bad quotes” or quotes of 40 words or more. A good writer should be able to effectively paraphrase most material. This process might be time consuming, but the effort pays off! Quoting must be done correctly to avoid plagiarism issues.
If your school doesn't have a plagiarism check here are some useful tools that you can use to check for plagiarism
Free Plagiarism Checker http://smallseotools.com/plagiarism-checker/
Copy scape, Premium Plagiarism Checker, Requires a small fee but its faster and more reliable http://www.copyscape.com/