Remember that plagiarism is often unintentional because it's easy to copy and paste.
The best way to avoid it is read the entire document you're citing and taking notes on it in a separate document from your draft essay, then read other resources and take notes on them, all of it before starting your draft essay.
Paraphrase (and cite) everything that you would consider outside of common knowledge. Don't paraphrase an idea that you consider so commonplace that your audience already knows it, because that's not the point.
Think about why you're using it - is it supporting or disproving your argument in some way? That support should be the focus of the sentence or the sentence(s) immediately after it.
Rewrite the idea so that it's supportive of your original idea statement, rather than a rewrite of the exact same idea without any clue of how it's helping your argument.