Use as wide a variety of link platforms as you have access to, and read the page below on how to handle the anchor-diversity...
http://www.backlinkbanzai.com/GooglePenguinPart2.htm
...This will cover the basic metrics you need to be working towards, together with an understanding of how to extend your keyword pool etc.
Also, you need to make sure you're pushing a constant and sensible link-velocity; try to avoid big swings.