There are few simple ways of avoiding plagiarism that every author shall remember. This list is a very short list of what you can do to make your paper more original!
Read and take notes - use as much literature as possible on the assignment set by your lecturer,
Take your time - you always need a time to write down your idea, don't hurry up, make it accurate!
Use your own words - ultimately to write a correct academic text you need to set out your thoughts, arguments and evidence,
Credit a text fragment correctly - indicate the author, add a quote and indicate it at the bibliography,
Don't forget to credit all fragments of the text you have used, all passages shall have reference to author, not only one of the fragments,
Avoid blind paraphrasing - think carefully about the meaning of the text you want to present and write it in your own words, always credit, if it is a creative and author's text,
Always list the sources you have used for your written paper,
Use a plagiarism checker - it can always be of help and show you exactly where and what you have copied and forgot to credit, either intentionally or unintentionally.