Be prepared for them to ask "how much are you making now?" or "What were you making at ...." as it's just another way to justify a lower offer. So while, I've sometimes been successful deflecting that (explained that a new contract wasn't the same work as a previous contract, etc), I've never found the right way to deflect this without coming off as outright rude. So I've done similar to Mozar's approach above and in the first instance, when I tell them my current salary, I include any benefits, bonuses, etc. So if making 75K, I might say, "85K, including bonus". They just hear the 85 and then start negotiating up from there.
The first number used though is the anchor -- so start out higher -- even if you have to include the value of every company-paid lunch or gift given to you as justification for the higher start.