I use a few various methods:
Generally I manually write 1 article, (usually academic journal worthy, if you don't have the education to do this you probably will have issues trying)
I then create 10 replacement sentences, all equivalent to the sentence before using totally different sentence structures etc
For instance:
Decades of research has provided only vacant, easily dismissible evidence on the effects of <keyword>. turns into "The evidence acquired so far through medical research has correlated only loosely with <keyword>" turns into "Though some research has offered results of statistical significance, the data is by no means overwhelming concerning <keyword>'s beneficial effects."
Obv after that you use your thesaurus + spinnerchief (or if you bought bestspinner) to spin the words into REAL EQUIVALENTS!!!!!! DO not use crappy synonyms.
evidence is not synonymous with "testament"
You're effectively writing 10 articles, but you can turn them into 1000, with a 97-98% unique rating, no editing necessary, and will be autoapproved at even the most "unique content" nazi sites (or anywhere where your category fits in).
Obv you cannot buy articles to do this properly (or really to have any legit success with articles in general)