In analyzing an audience, you must understand how the audience data was collected. Is this first-party observed data, merged data, sampled data.
How are the demographics for the data collected?
Establishing these helps you understand your data foundation, is what you’ve got rock-solid enough to build conclusions on top of. If it isn’t, where is it weak, as you need to acknowledge that in your conclusions.
Often we have to make decisions off incomplete or proxy data. But establishing that upfront avoids any confusion.
Then, take your audience data, break it into clusters, and compare it against your other metrics. This will help you see trends or patterns which help drive insight.