This is a really basic technique, but its one that I come up with the other day, that makes writing a little easier -
First of all, you research a topic. So you search on Google and pull up a couple of websites. If you want to do a sort of "rewrite" then just pull up the top or most comprehensive result. If you want something slightly better, then repeat this process across several websites/articles.
Read through the website and take in the information. As you go through the article, write down bullet points for anything that seems like relevant information.
Once you have this list, you can look back through it and add a few references or links if needed.
Then you just write a new article out, using the list of bullet points that you made, along with any references that you added to the list.
This is essentially a way of rewriting an article whilst also insuring that it is 100% unique.
If you want to make it a little more comprehensive, then you can repeat this process using several websites or articles, each time added points to your list then organising the list so that the relevant points are grouped together in a logical way and then rewriting the article based on that list.
I done this recently for a music website that I run, I wanted to write a biography on someone, so I looked them up online, took 4 different locations where they already had write-ups read each one and made a list for each one, then put the lists together so that relevant information was grouped together, then I used the list to write out a fresh biography in my own words.
The result was a longer and more comprehensive biography than any of the individual websites that I used as references had.
Just to show you that this method works, here is the keyword that I am targeting. I already had content on the website for this person and it was not ranking in the top 100 despite being on the site for 2-3 weeks. I only rewrote the text a few days ago using the above method and already the keyword has jumped from nowhere to #53.