Drop Shadows between fabric and skin

I see alot of the better quality clothes in SL have a drop shadow between the texture and the skin, like on short sleeve shirts, at the end of the sleeves, on tank tops around the chest area, giving the impression that the texture is a separate layer and not intact just painted on which it really is. I've tried to re create this effect and not had much luck, was hoping someone may have a little insight into whats the best method to use to effect. The best I've been able to do so far is create a dark line where I would want the shadow to be which looks very unrealistic.

I don't use Photoshiop and I'm not familar with it so if you are a PS user I'm sure there's a filter/effect that accomplishes the same. Look for "drop shadow" or maybe "perspective shadow". Those both will work in GIMP so I'm sure they will work in PS and Paint Shiop Pro too.

Play around with the shadow blur, radius,, color, etc. You can get some really good effects. If you are using transparent or semi transparant textures for your fabric you might have to play around to get the "shadow" that is under the layer you are applying the effect to look realistic....maybe removing that part all together. That would depend on the texture.

alot of people also use a 3d editor like poser or maya that will all you to set up lighting and bake highlights and shadows into the textures.... I haven't played around with it much so I'm not sure it it'll do edge shadows like that, but it IS a very effective technique for adding built in depth to clothing layers.

I manage the effect in Photoshop by adding semitransparent shading in the alpha channel. The line of shadow will be a shade of grey graded into the solid black of the transparency.

The colouring of the actual shadow on the texture could be a dark tone of any colour but I find a dark blue works best if you like a marked contrast whereas sepia blends in for a more subtle effect. Neutral grey doesn't look at all right to me.