Creating Custom Shapes

We will start off with the following image:

At present, we have the image on one layer with its own white background, and then a background layer filled with white. What we will do is delete the white background from the monitor layer. Choose the Magic Wand tool and select its background:

After deleting, we still have the shadow left, so let's tidy that up. Choose the Polygonal Lasso tool and select the shadow (you might find it easier to zoom in - Ctrl+, and Ctrl- to zoom out):

We should now be left with just the monitor. We will also make a selection of the screen with the Polygonal Lasso tool and delete it:

Now we want to Ctrl-click the monitor layer to make a selection, then select the marquee tool and right-click the selection on the canvas and choose Make Work Path. We can leave the tolerance as 2.0

PhotoShop will then create a Path for the selection we had. We can hide the monitor layer to show it:

If we're happy with the path we can leave it as is, but let's perfect it a little. Choose the Pen tool, reduce the opacity of the monitor layer to 50% and zoom in. If you hold Ctrl while using the Pen tool, you can select the Path and also move anchors around. But first, let's add a new point in this corner, where it is too curved:

Just move your mouse over the path where we want to place an extra anchor until the Pen cursor has a + icon next to it. Then click once.

Now that we have a new anchor, Ctrl-click and drag the anchor into the corner, like so:

Next, choose the Convert Point tool () under the Pen tool, and then click and drag the arms coming from our new anchor to line up the base of the monitor:

Do this, modifying anchors and arms, and adding anchors where needed around the whole path. We want the path to fit as closely to the edges of the monitor as possible.

Once we have perfected the path, it may look something like this:

Once we are satisfied with our shape, we can then goto Edit > Define Custom Shape..

We will then be prompted for a name. Name it Monitor, and click Ok.

Now when we choose the Custom Shape tool, we will be able to choose our new shape at the bottom of the list:

Using this custom shape, we'll be able to scale it to whatever size we want.