It is very tempting to give away equity. WHen you have a startup it seems like worthless paper - after all 10% of a company worth a few thousand dollars is a lot less money than paying them - right?
But think of your unicorn. 10% of a billion dollars is 100 million. Is their advice worth that. Because you are tied to that valuation for ever.
Be more pragmatic. Think about what motivates them. For some it will be money, for more it will be about helping people, making a difference - or perhaps they are just engaged in the problem being solved.
I see it like a present. Stock options are like the gift voucher - little thought behind it and it takes a lot of money, but isn't seen as having that much value. Put some thought into the present and you'll get more engagement, more perceived value and a real shared sense of purpose.