Know your worth well enough that you don’t need someone else to price you.

With no sense of your own value, whatever number somebody else offers becomes the number. That shows up in pay eventually, and much earlier in smaller places: how much of your time you give away, what you put up with, what you accept as fair for your effort. Someone else’s estimate always arrives with their interests baked into it. Yours at least contains your information.

Before the next thing you agree to, decide privately what it is worth to you. Say your number or your terms first if you can. Being wrong about it still teaches you more than never having had one.