I don't really haggle anymore as such. What I mean is I know what I'm going to pay and if they don't like I leave and go next door where usually they have exactly the same thing and at my price. Or so close to my price it does'nt matter.
p.s. Bafana's idea is a good way to start haggling if that's what you want to do. I love the expressions on their faces when all you offer is a third. LOL