Depending on where you are in your business, and what you're trying to do, you need to be measuring different things. Open up your dashboard or insights page and you're going to face a plethora of information - where do you begin?
Social media data doesn't need to be difficult, but first, you need to know what you're trying to do (otherwise, what does an increase in follower numbers mean for your business? It doesn't necessarily lead to more sales). As a brand, you need to be careful about measuring the right things, as an agency you need to be honest and help your clients and guide them to things that actually help their business and not just vanity metrics (in most cases impressions are meaningless without further data points).
Don't get sucked in measuring the wrong things, and don't blindly try out tactics on social media if you aren't measuring and recording data. Work with your data and get more meaningful results.
If you're a small company and growing you need to measure different thing - I wrote about this in detail on Medium and you can read it here.