It describes what you do.
So, make it count.
Say, you're a landscape designer.
Your first thought might be to use your title,...
...but he's also a landscape designer and so is she.
So, how can you stand out from the crowd?
Use your LinkedIn headline to show off your unique expertise like ecological design.
While you're at it, why not add your passions like beekeeping?
Congratulations, you now have a LinkedIn headline that sets you apart from your peers.