Colour Confidence published 10 tips for monitor calibration. Paraphrased:
Tip 1 - Take the ambient light into account
Tip 2 - Colors surrounding your monitor impact the colors on your monitor
Tip 3 - Don't overdo the brightness.
Tip 4 - Turn off auto-brightness
Tip 5 - Remove Adobe Gamma
Tip 6 - Default settings: Luminance 90, Gamma 2.2, Temperature 6500
Tip 7 - Warm your monitor up first
Tip 8 - Repeat first time Calibration
Tip 9 - Compare to print
Tip 10- Calibrate once a month
You can download the full text here.
You can use our free Calibrize utility for Calibration. But hardware calibration tools always yield better result.