My preferred technique is to mentally baseline my current total comp, then shoot for that as my base at my next position.

You really shouldn't compare salaries, since benefits can vary so much.

So if I'm making $100k in base now, but have a good bonus structure, a good vacation package, health, retirement, etc., could make that total comp closer to $150. So that's what I say is my current compensation -- most people will anchor to that in salary negotiations.