Okay, here's how you do em:
Make a new rounded rectangle shape. The corner radius should be between 4 and 8 pixels if you're working on screen resolution, obviously bigger if you're working in print resolution. Litter that sucker with guides:
Make sure that you have guide snapping on:
Don't forget this, though:
make a selection of twice as wide as your rectangle's corner radius was, snap the left edge or right edge of the selection to first the left edge guide and then the right edge guide, respectively, and make another (2) guideline(s) from the opposite vertical edge of the selection:
Now, on to the swirl path.
Switch to the Paths tool:
Mak sure that the Paths tool is in "paths" mode, not "shape layer" mode:
Start by creating a point at the intersection of the guides you placed on the left edge and the bottom edge. However, once you place the point, don't let go of the mouse button; instead, drag upward until the diamond revealed by the drag lines up exactly with the intersection point of the left edge guide and the middle horizontal guide:
Here, the order in which the points should be created is shown. Boxes and arrows indicate where you should curve the path by dragging in the corresponding direction. The first point and the fourth point are the only ones that require this; the other points can be made by simply clicking. Don't forget to close your path after point 5 by clicking on the first point you made.
Now that we have the swirl path, let's make some Aqua!
Select the area of your rounded rectangle shape by Control-clicking on its "layer thumbnail" (not the vector path to the right of it). Next, switch to the Paths tab, located in the same palette as the layers and channels tabs. In order to get the correct selection for the swirl area, you must intersect its selection with the rounded rectangle's selection; do this by holding the Command key, the Option key, and the Shift key (yes, all at the same time
) and click on the path thumbnail of your "work shape". You should get a selection that looks like this:
Switch back to the Layers tab. Create a new layer. Switch to the gradient tool, change the gradient to "Foreground to Transparent", the second preset in the list, as seen in the Options bar at the top of your screen. Press D and then X to reset your foreground and background colors and switch them, making white the foreground color. Drag the gradient tool from the top edge guide to the bottom edge guide. Deselect.
Now, the bottom gradient...
Reselect the rounded rectangle. Switch back to the Paths tab. This time, hold the Command and Option keys only and click on the path thumbnail. You should get this:
Switch back to the Layers tab and make another new layer. Select the Gradient tool again, using the same settings as before. Drag the gradient from the bottom edge guide to the horizontal middle guide. Deselect. The bottom gradient looks best if you change its blending mode; I usually use Overlay. Switch blending modes by selecting the bottom gradient layer and choosing overlay from the drop-down menu at the top of the Layers palette:
Okay, that's pretty much it. Mess around with Bevel and Emboss settings and Strokes and you're good to go:
Top