Having said that, here are some tips on how to spin your articles the right way:
Review your spun version carefully and criticize it as how a devil's advocate would during a canonization process. In this way you will be a saint in Google's eyes.
Make sure that your spintax is flawless and that you haven't put on an extra bracket or missed one.
It is highly-recommended to spin an entire sentence than do it verbatim. In doing so, the spun article would be more readable compared to a spun version where the words were just replaced with synonyms.
Highlight the sentence you intend to spin and focus not on the words themselves but on the idea of the sentence and look for ways how you can revise the sentence without compromising its idea.
These are just general tips in article spinning so please don't limit yourself to these rules. Every writer has his own style of writing. In the end, article rewriting will still remain an art that can only be mastered by humans, an art where skill and talent determine the quality of the articles spun. Spinchimp is a free article spinner that can really help you in rewriting articles.