How to build democracy?

Explanation:

We live in an age in which democracy – save for a few notable exceptions – has been largely accepted as the most legitimate form of government; a time when elections of some description regularly take place in the vast majority (68.9%, according to The Economist) of countries around the world. In the modern world, even the most despotic leaders recognize the popular vote as a legitimizing mandate for government - which is why some endeavor to rig elections in their favor.

In Africa alone, estimates are that around 16 presidential and legislative elections will ta place in 2015. But what does it take to build, stabilize and consolidate a modern democracy that lasts? What lessons can we learn from the most successful democratic transitions in the world, and what cautionary tales can we learn from the worst?