Zphix,
In one of Chase's articles he exhorts us to "open from the side", which makes perfect sense to me... full-on frontal body language, "cornering" the girl, is to be avoided, while startling her from behind is quite possibly even worse!
My take on his mantra of "open from the side" is as follows: I get the best receptions in daytime street approach when opening from one of two angles.
1. Oncoming foot traffic: the girl is coming toward me in the opposite direction, on the same side of the street. As she draws closer I check her out with my peripheral vision and do not make eye contact. Sometimes I catch a glance from her from the corner of my eye, which is like an open invitation. As she draws level to pass me, I open from the side.
2. Opposite sidewalk: the girl is walking in either direction but on the other side of the street. This is a cool opportunity to be noticed, especially in broad, major city streets, but obviously higher effort. I skip across the roadway (obviously when it is safe to do so without being mown down by traffic) and as I step onto the opposite sidewalk I approach from a diagonal angle. Any woman can see you coming this way, and is ready for your opener as soon as you draw level. Because of the higher apparent effort, I have to go very direct as early as possible in the approach.
As I was starting out I tried approaching from behind, waiting for a moment for her to "take me in" as I caught up before opening, but now I have a few dozen approaches under my belt, I have realized this works less well. It lacks spontaneity and gives the impression you may have been "stalking before pouncing", which unnerves the girl.
-Marty