So my favorite thing about Photoshop isn’t that interesting, but I use it on a daily basis (because yes I am on Photoshop daily because I am that awesome). Anyways, this little trick is the refine edge button. I used this when I cannot get the edge of what I am selecting perfect. It also allows you to create a softer edge on something that is selected so that it looks more natural if you are fiddling with the background of an object.
This button can be located after a portion of a picture is selected on the bar underneath the toolbar, the first one from the right. ( I know it is there on CS5 and CS6, I can’t be held accountable for the other versions).
When you click it a little box pops up and you get to pick some awesome settings. These include radius, smooth, feather, contrast, and shift edge. When you adjust the radius it just chooses how many pixels you want to be working with. This means how much of the edge you want to smooth or what not. Smooth when adjusted does exactly as it sounds, it smooths the edge that you have selected. This really helps when you don’t have a very steady hand. Again feather sounds just like what it does. It feathers the edge. This helps when you want to fool around with just the object and not the background of vice versa, it makes the edge not at sharp so that there is a smooth transition between the two components. Shift edge means that it will move the edge to make the selection around the object a little smaller and or little larger. This helps if you have not selected something perfectly at its edge. Contrast, to tell you the truth, I have no clue what it does, so obviously I have not found a use for it. You could probably find a use for it if you decide to fool around with my awesome awesome trick.
Like I said, its not the most interesting thing you can do with Photoshop, but it does come in handy especially when you can select that edge just right even after fiddling with it for hours. It has definitely saved me a whole lotta time.