The Neg comes in when you feel that you need to take her down a peg.
Really attractive girls in nightclubs generally will need them, because they are being hit on by intoxicated chodes all night and your instantly classed as one.
During the day less guys will talk to HB10's e.g in the Mall, the Gym (etc) so you don't really need to dish them out as much but through practice you will learn when they are appropriate.
e.g
PUA: "Wow love your outfit"
GIRL: "Thanks"
PUA: "Shame about the hair though"
GIRL: "What's wrong with the hair!?"
PUA: "It's a mess!..here i'll fix it" (leans in and fixes it)
GIRL: (gets all wet and shit.. well she would if it was me touching her)
Notice the inclusion of touching her hair (KINO) another little tool for spiking attraction. It's perfectly acceptable since you are fixing it for her.