First ask: "How will I use this data?"
Whether it's during data conversion, adding a new data field, or reconsidering a given process, one of the first questions you should ask is "How will we use that data?"
Put another way, just because we can manage the data doesn't mean we should!
For example, I was speaking with a client recently about how to manage organization records within their database. They have individual members and want to associate all of the individuals with their appropriate organizations. It's an understandable desire. But when asked the question "How will we use that data?" the answer was "We're not really sure."
We all have lots of data we need to manage. And lots more we might want to manage. But for any data we manage, we need to be able to quickly answer the question "How does this data get used?" If we can't answer that, it's probably not data we need to be managing!