Bella's the same, she's 4 now, used to be really difficult, alot better now.
It's like a little ritual. I get her collar she gets all excited, we put it on, I pick up harness, she runs off, I say 'come on Bella' she ignores me, I say 'now', she comes begrudging over, harness on, she gives me a kiss, I tap her bum and say upstairs, back to being excited Bella.
I keep saying I'm going to start putting her harness on first collar second to see what she does.