In a nutshell, to get maximum re-tweets you need to:
1. Make your tweets 100 characters
2. Say Please Retweet
3. Tweet on Friday lunchtime between noon and 2pm
4. Include a URL and a hastag.
And if you can do all of that in 100 characters or less, and make it a compelling and interesting read then you're a genius or a magician! Good luck.