I don't consider myself an expert at all, but the way I approached it is that I went in knowing roughly what it would take for me to move, and expecting that they wouldn't match it. So I was comfortable asking for that amount even expecting them to not be able to meet it, and I was comfortable rejecting offers that didn't meet it. And so then when they did meet it, it was a pleasant surprise.

I think most of what people talk about "negotiating skills" or "driving a hard bargain" is pretending to be in this situation despite it not being true. But in my case I genuinely was in this situation, so I did not have to use a lot of skill (besides the mental aspect of being confident in how I felt)