Depends on the chick. I usually get a general scope of a person, take into consideration the situation and come up with a plan devised from who they are and cross-referenced previous experience. This means that if I have to adapt on the fly, I can. Nothing worse than sounding scripted.
And essentially, yeah. Her triggering the memory of another could be lethal, because I have a nasty habit of changing my mind about how badly I really want something based on a negative impulse and it can be too late or time-consuming to recover if I reconsider. However, forcing yourself to see someone in a context you desire is bad too, as you can fail to pick up on many of the idiosyncrasies they have as an individual. It's important to notice these as being perceptive puts you ahead of the pack and people become much more forgiving of your own short-comings if you notice the little good things about them. Idle commentary on how they look sexiest when they put one hand on their hip and the curve of their body when they're thinking or when they seem to be most confident makes my being an egotistical, cunning son of a bitch a whole lot less of a bad thing in a second consideration. So long as the noticing is put into an empowering context, you can nearly be and do anything you want.