Outright saying I'm currently on X has worked wonders for me. X is 20% more than what I actually earn.
Bad advice if your value delivered is 100-200% what you currently earn (which can vary significantly based on the organization into which you deliver it). This can mean the difference between having a boat to retire on or not, after compound interest.
I don't think I have the stones to push for 100% - 200% increases...