Skipping the Dialog Boxes
Photoshop CS6 Tutorial
How to Avoid Dialog Boxes in Photoshop
Dialog boxes are helpful for entering names, changing options and customizing the box. There are several times when you want to just skip the options and accept the defaults. The trick to avoiding the dialog box is to press and hold the Option key or Alt key on a PC.
Open a new 500 pixel by 500 pixel Photoshop document (File > New).
The document should have a single Background layer. Double-click the Background layer icon to convert the layer into a transparency layer.
A dialog box appears. Press OK to accept the defaults and convert your layer.
Now let's repeat the process and avoid the dialog box. Choose Layer > Flatten Image.
Option (PC - Alt) double-click the Background layer icon. It is instantly converted to a transparency layer.
Try This with Other Shortcuts
Often times by adding Option (PC - Alt) to a common shortcut or icon click you can simplify your workflow.
For instance, you may want to add a Layer Mask. Clicking the Layer Mask icon creates a white mask. Option -clicking (PC - Alt-clicking) the Layer Mask icon creates a black mask.
Background to Transparency Method #3
Another way to convert a Background layer is to drag the small lock icon from the Background layer to the Trash icon at the bottom of the Layers panel.