This is a very big subject but for me best practice is about eliminating as many variables as possible on and around the press. You need to look at each aspect of the print process and determine what you believe to be the most effective in helping you to achieve consistent results.
This usually starts by measuring and recording what is being done to help to determine if it is repeatable and if the results are acceptable. Generally the use of measuring devices such as spectrophotometers, densitometers, video web inspection, interferometers, viscometers are necessary to help capture the necessary data in an accurate form that can then be repeated and measured accurately each time a job is run.
Always try to get your suppliers involved at the earliest stage possible as they will then be able to assist you in achieving what is best practice for you and your company and more to the point, how to define it.