As always the main rule you need to live by is value the equity at zero and you'll be (maybe) happy. Short of being a founder (and thus not really being offered equity) I have never treated these things as anything beyond a minor on paper "bonus". Given you'd be lucky to get anything more than 1% even as a first employee I find them next to worthless as early stage motivators. Which is how everyone seems to play it -…
This advice is often given but it's easier said than done. Let's say you work at a unicorn for 3 years and in that time it goes up 10x in VC fantasy land valuation. On paper you have a lot of money and the company reasonably might go public a couple years after you leave. Let's say you're granted about a year's salary in shares when you first join so you've vested $100K for a round number. When you leave that equity…
Instead, I bought a fee thousand dollars worth of shares - only what I could afford. They IPOed at 10x, and I made a down payment on a house.
But that was a rare case: I had some extra savings, the company was clearly succeeding with clear intent to IPO. And even so, I had to wait four years for a payoff.