Sometimes, acting like you don’t need X job also works wonders. Don’t be afraid to turn down the offer and walk away, because this shows that you’re capable of going somewhere else and getting what you want. There are other places that will understand your worth and will ‘make an offer you can’t refuse.’
11. Never negotiate after getting the offer letter

Well, that’s just a stupid move because all the talks needed to be done before the offer letter was typed out. If you argue after you get the offer letter, HR is never going to listen. Moreover, this could also lower your chances of getting a higher appraisal in the coming year, as you'd have left a bad impression on your company.