A lot of LinkedIn experts seem to have no idea.
I haven't received advice from one, but I've noticed that a lot of people have.
One tip is to not say what your role is, but to list a couple of great qualities you have.
"Iain Duguid - Passionate, effective, results driven."
It looks ok on a computer, but on a mobile it might look like:
"Iain Duguid - Passionate, effecti..."
I would rather see what a person does, so I prefer this:
"Iain Duguid - Creative Copywriter, Native Content Creator - Passionate, effective, results driven."
Even if LinkedIn cuts off my description, it still says what I do.
Some people write a sentence in there like "I lead various projects which see an improvement of..." and it's cut off. You could phrase it better by saying "Improved projects by 300%."
Learn more about word economy here.
Another thing to mention: Show your point of difference. What sets you apart from everyone else? I'm certain EVERYONE looking for a job would describe themselves as passionate, effective and results driven.