You can probably see that the document size is displayed by default at the bottom of the document window in the Status Bar, but did you know that clicking on the arrow to the right displays additional display options (such as document profile, dimensions etc.)? And, regardless of what information is displayed, if you click and hold on the information, the documents width, height, channels and resolution are displayed.
In Photoshop CS4, if, you prefer the legacy “cascaded” view as your default when opening multiple documents, select Preferences > Interface and uncheck “Open Documents as Tabs”. To display cascading images with the Application Frame invoked, select Window / Arrange / Float in Window or Float All in Windows. If the Application Frame is not invoked, select Window / Arrange / Cascade. Or use the Arrange Documents icon on to toggle between floating and cascading. And don’t forget, if you are using the same menu items several times a day, make sure that you assign your own custom keyboard shortcuts (Edit / Keyboard Shortcuts) to the ones you need most!
Most of us probably know that tapping the Tab key will show and hide your panels and Tool bar, and Tab + Shift will hide and show only the panels, but did you know that while the panels are hidden, you can auto show/hide them by positioning your cursor to the edge of the application? (Unless, of course, you’ve turned off this behavior under Preferences/Interface.)
When selecting multiple objects with the Move tool, you have the option to check “Show Transform Controls” (in the Options bar) to have Photoshop display a bounding box around selected objects (content on layers). Not only does this help to show which layers are selected but can also be used to quickly transform an object without having to select the Free Transform command.
Option (Mac) / Alt (Win) -drag a layer in the images area with the Move tool creates a copy of a layer. You can also Option (Mac) / Alt (Win) -drag in the Layers panel to duplicate a layer - select the layer(s) and drag until yo see a heavy black line between the layers and release.
In order to drag-select multiple layers, select the Move tool and check the Auto Select option in the Options bar. Click and drag over objects with the Move tool (in the image area) to select the layers. This method works well if you have multiple objects (layers) and a Background. Otherwise, because you have the Auto Select feature turned on, clicking in the image area will select the first layer that you click on and begin to move it instead of selecting additional objects (layers). Note: because a Background is locked by default, it is impossible to select and therefore skipped by the Auto Select Feature. So, if you have layers that you do not want to auto select, lock them. If you prefer to keep the Auto Select Layer unchecked (off), with the Move tool selected, you can use the keyboard shortcut Command (Mac) / Control (Win) to temporarily turn on the auto select functionality.
If the Move tool is selected, holding the Command (Mac) / Control (Win) temporarily activates the Auto Select (Layer) feature. To use Auto Select, simply click in the image area over the desired layer to select it in the Layers panel. Note: if you prefer, you can check Auto Select (available in the Options bar when the Move tool is selected) to eliminate the need for the modifier key. To select additional layers, add the Shift key while clicking. To Auto-select a layer using the context sensitive menus, Control (Mac) / Right Mouse (Win) -click in the image area over the desired layer and select it from list.
While another tools is selected, holding the Command (Mac) / Control (Win) temporarily accesses the Move tool. Releasing the key returns you to the previous tool. Note: the Slice, Slice Select, Pen, Path Selection, Direct Selection, Shape and Hand tools are excluded from this shortcut.