Had some time tonite, so I thought I'd mess with this, its kind of a finnicky thing to model since its so thin.

 

What I did was a lot like what PhilC said, I made a real plane, unfolded it, then scanned it flat, that gave me a guide to work with and also a base for the texture.

I made a rectangle over the image of the correct size, then sliced the polygon up to match the folds. Then I color coded the pieces and UV mapped what I had [cause I knew it was best to UV it while it was flat]. I only concerned myself with half, cause geometry can be mirrored and UVs flipped. Now I took a bit of an unconvetional direction for actually folding the plane because I unwelded/split all the verts. Then I started folding it the way you'd fold the plane. after each fold tho, I'd move the "overlapping" polygons up [ or down depending on the fold direction] so that there was a little space between each layer of polygons. Once I'd folded the 8 pieces into the correction positions, and offset them as needed, I went back and bridged them with thin polygons to give the illusion of folder paper with a little thickness. So I ended up with 8 big pieces connected by 7 thin strips. Then I just had to adjust the UV map to account for the thin strips, mirror the whole thing, and texture it.

 

 

When looking at my paper version, I noticed there was some bend to some of the folds, so I divided some of the polygons that had the most bend to them, and gently bent the model to account for that, and give a more realistic look.

It occurs to me now, you could get the exact directions for the cuts without scanning or even taking a picture of the flattened paper version, because the first fold is a 45 degree fold, and the next two folds are half, and half again, so 22.5 degrees, then 11.25 degrees. So you'd need cuts at 11.25, 22.5, 33.75, 45, 56.25, 67.5 and 78.75 degrees [if I've done the math correctly].

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