Westernization allows a country not in the western tech group to remove the penalty on technologies. However, Westernization is an expensive process and will severely disrupt a nation for decades. To begin Westernization, at least one Western neighbour must be ahead in technology by 8 total levels. It also requires a fairly large stockpile of monarch points.
Should I deliberately fall behind in technology straight away, or wait until a later period in the game?
How does playing as a nation with a smaller penalty (such as the Eastern or Ottoman group) or a larger one (such as Mesoamerican or South American) affect the "right" time to begin?
Is there a particular date or technology level (based on which technology group I belong to) where it is a good idea to begin to stop coring, vassalising and spending points on technologies, and instead save them up to begin the process of Westernisation?
In a nutshell: When is the optimal time to prepare for and carry out Westernization?