The only way to do this is to either write them yourself or pay someone to write them for you. If you mean a software, then there is some good software around for instance The Bestspinner but for solid unique content the it is better to write fresh content.
You need to do some research (on both topic and keyword), read more related book, then use your own word to write an article, also include your personal opinion.
You have to write the article itself that there was no twin, but if you do not have time to write, you can purchase the article according to your niche site
Article Spinner! just jumbles the words only for same reason meaningful purpose of article get effected. For generating unique content you can follow for ideas on article directories and then after ideas compose in your language
Article spinners are used to mass produce articles, if you use it like most people Google will recognize synonym replacement and even if the software says 70% unique or whatever it won't be as effective as writting a new article. Go to an article directory and you can do some quick research.
write your own content or pay someone to write it for you and then check it with copyscape. While many marketers cringe at writing their own content, it's the one thing that can set you apart and bring you in a lot of money because you'll have high quality and very long term if not permanent backlinks.
If you don't have prior knowledge in writing, you won't able to write unique article for your promotion. Better yet, you visit the content thread, there are lots of articles being sold there, in a cheap price.
"Make" unique articles by answering the questions on this page: http://www.outsource2documaker.com/wp/2010/11/suggested-points-to-cover-in-articles/
there is no such quick process which will create great content overnight. Research information online, arrange them points wise according to the importance and express them in your own words.
well for the unique content try to check the uniqueness of your articles using the spinner or try to write related niche..and add backlinks to your articles in the last portion..Hope it will help...
If you use an article spinner, dont just spin the words, do the sentences, this way you can have totally unique articles and this adds value providing the articles are of quality.