Perhaps one of the best practices in PMI is to establish the integration team early on in the process and make sure it’s representative of the various business functions of both buy- and sell- sides. With the appropriate confidentiality controls, this could be as early as the commissioning of due diligence process. This will allow ample time to lay ground for PMI and to identify challenges and address them early in the process.
Establish a framework for decision making process.
Establish an IMO and dedicate integration resources.
Access and measure cultural progress continuously.
Ensure operational continuity and maintaining customer focus.
Focus on priorities: opportunities with highest value and highest probability to succeed.
And most important, continuous communication.