Here we have the complete figure of Spidey swinging before adding those crazy black details in front of this all black background I had to go with for speed purposes. (Go ahead, click to enlarge)
Here, I've added in the blacks that kind of blend the edges of his body into the background (had I the time, I would've added in some kind of contrasting element be it stars or a building or two), but still there was something missing... (Click it and see it easier, old man)
So I gave him a bit of a forward tilt and that seemed to give him the kind of pose I was looking for, more aggressive looking.
(For a closer look, click the image, ya dang fool!)