Rewriting PLR articles is not really all that difficult. On thing you should try to do is make your articles
LSI (Latent Semantic Indexing). That means that your use of keywords/phrases should be themed around your article.
In other words don't pepper your articles with keywords that are not closely related to the theme of your article.
Google spiders check sites for that now.
Using "Long Tailed" keyphrases will work best in a article.
IE: An article about acne. **Acne And Pimple Treatment** or **Acne On Right Side Of Face** would work very well in the article as long as the article was featuring facial acne problems. BTW. I pulled these keyphrases using the google KW tool. at
adwords.google.com/select/KeywordToolExternal
Click on the "Site Related Keywords" tab. To get the sites you want to check out just open another window and do a Keyword search that you are interested in and then Copy/Paste the URL into the spot in the Google KW tool. Doing the top 10 sites usually returns some pretty good KWs.
Hope this helps a bit
RT...
An Add On: Here is a free web tool that I find very handy to have.
Keyword-density-tool It's on the "Article Underground website.
NOTE: I don't belong to, or promote "UnderGroundArticle" . They provide a couple of free very good web tools and also some very good videos about articles.
The
Keyword Density program is a good way to check and see how your site stacks up to Google.