When you double-click a layer in the Layer Palette, you will access the Layer Style dialogue box. Here, you can set many eye-catching layer styles such as Bevel & Emboss, Drop Shadow, Inner Shadow, etc.

The lesser known secret of the Layer Style dialogue is that when you move it out of the way so that you can view your canvas, you can actually control the position of your current layer style with your mouse by dragging it!

The above technique works for these layer styles:

Drop Shadow

Let us start by applying Drop Shadow to a layer. After you have checked the Drop Shadow checkbox, drag your Layer Style dialogue out of the way to view your object on the canvas. Now, just position your mouse anywhere outside of the dialogue box and drag!

Notice that as you drag, the drop shadow will follow the mouse as if it were a layer underneath your object! The values for angle and distance will adjust automatically. This holds true for Inner Shadow too!

Satin

For the Satin layer style, this technique will control the Distance and Angle values of your satin effect. The closer you drag your mouse towards the centre of your object, the greater the Distance value. The Angle value is adjusted according to your mouse position at the perimeter of your object.

Gradient Overlay

For the Gradient Overlay layer style, this controls the "centre of the gradient". Just drag the gradient to set the position of the gradient overlay.

Pattern Overlay

For the Pattern Overlay layer style, this technique sets the offset of the pattern.

For Unsupported Layer Styles...

For layer styles that are not supported by this technique, dragging your mouse out of the dialogue box will pan the layer to adjust the view of the canvas. You can also Zoom In/Zoom Out while in the Layer Style dialogue; just press the CTRL + PLUS SIGN or CTRL + MINUS SIGN combinations to zoom in/zoom out.