In writing manuscripts, I usually use some familiar expressions, optical components, and familiar abbreviations and this increase the plagiarism ratio. what is the accepted ratio in manuscripts?
I think its best to avoid familiar expressions and rewrite them in your own words. But don't worry about technical terms; you have to use them! Also, avoid abbreviations; I didn't use a single one in my PhD. You'll never get into trouble for writing words in full and abbreviations can be confusing. I would go for zero as your accepted level of plagiarism.