1). Having a proper security framework in place that offers multi-dimensional security and allows visibility into threats that a) attempt to get into your network, and b) already exist on your network.
2). Governments should work with the private security sector to improve the overall security of the threat landscape. Corporations should also work with security vendors to better understand the threats that are on their system.
3). Understand what assets and weaknesses you have in your network.
4). Educate. Hold security briefings or seminars for everyone involved on the network.
5). Have proper security policies in place like password enforcement and use two-factor authentication/ token-based security technology.
6). Have a proper IRP (incidence response plan) in place. Be prepared to deal with breaches by thinking about possible attack scenarios and what you would do ahead of time.