When working on a webdesign, my PSDs always have dozens of layers. I recently wanted to change the font-family of the layout. I started to go every layers and make the change. Feeling I was doing it the old way, I found that Photoshop has a great tool call the Layer Filters.
Suppose your Photoshop Layers window look like this :
On the top menu of the Layers window you can turn on/off layer filtering.
You can, for instance, filter text layers. Therefore the window only shows “type layers”.
Now by selecting every layers and using the Character window, you can change the font-family, font-size, color, etc… of every text layers at once.
Using the select menu on the top left you can filter layers by Name, Effect, Mode, Attribute and Color. If I choose the Effect option with the Drop Shadow value, the Layers window shows only layers with a drop shadow applied.
Simple and pretty useful :)