Best practices for market research

[Catherine M.]

I'm curious what others consider a best practice when it comes to market research. Would be interested in hearing what data you look for (e.g., population growth, job trends, average median income) and what thresholds you consider when deciding to start looking in a specific area.  Any sources of data would also be appreciated.  I do have practices for how I look into markets but wondering if I'm looking at telling data points.  Thank you!