In Photoshop, to hide all other layers, simply Alt-Click the invisibility icon (the ‘eye’ icon) of the layer (or group) you want to stay visible.

To restore visibility back to the way it was, Alt-Click the layer again.

It’s sometimes funny what new things you discover even after years of using the same tool.  Photoshop happens to be one of those tools.  The above tip is just a little something I figured out recently (by accident) that has really helped me when cutting up PSDs.

Why is hiding all other layers useful?  Say you have a layer that contains a logo with a glow effect and you want to create a PNG with transparency.  Selecting and copying won’t work, because it will not copy the glow effect.  You need to copy merged.  But if you copy merged, all the background layers will be copied as well.  You need to hide all other layers that show up behind the logo.  If there’s a dozen or so layers behind the logo, Alt-Clicking the visibility icon can be a very convenient time saver.