Know the market, know what other people are offering for your job position. Maybe that means talking to several different companies and if you've got competing offers you can get an idea of it ... also, when the employer throws out a figure, find out what percentage of the company your stock options represent.
It's like they say about soldiers coming back from war. People all around you are dying. Really dying, Eric. You go in for a week's chemotherapy and you're in a ward with people who are really, actually dying, there and then and doing their best to come to terms with it. When the week's up, you go home and you see your family and your friends and everything's normal and familiar. It's too much. You think - one world can't possibly hold both these lives and you feel like you're going to go crazy when you realise the world is that big and it can fill with the most terrible things whenever it wants to.