How to use "add/subtract/intersect from path/shape area" effectively in Photoshop?

Question

I'm attempting to follow the below Photoshop tutorial, but steps 29 and 30 have me stumped.

The larger of the two white rectangles in the below image was created on its own layer. Once I have that layer selected, it's actually impossible to carry out step 29, as the "Add to shape area" button is greyed out on the tool bar. I can only do this by first making the black rectangle on a new layer, then subtracting the inner white square from that...

Relatedly, I have no idea how to do step 30. This is for a pencil icon to place within the square just created, but it does not specify what layer this should be made on.

Is it possible I should have Paths selected rather than Shape Layers at the top? I've tried this, but it didn't seem to do the trick. Once I created a work path, I didn't know what to do with it in order for it to add or subtract from the below layer, nor how to add more paths and be able to manipulate each individually (in the case of the pencil icon...)

Any help here would be greatly appreciated!!

Answer 1

Okay if I follow things, based on the couple steps you've posted.....

For Photoshop CS5:

Select the Rectangle Tool.

In the Control Bar you want Shapes and Create New Shape Layer selected:

Draw the rectangle (A new layer should be created).

Now click the Subtract from Shape option in the Control Bar:

Draw a second, inner, rectangle.

Now click the Exclude Overlapping Shape Areas option in the Control Bar:

Draw the rectangle for the pencil.

Select the Polygon Tool, enter 3 for the number of sides in the Control bar (don't change anything else):

And draw the point for the pencil.

You can see all this in an animation here:
https://i.sstatic.net/sROUr.gif
(Purposely not posted inline to avoid large image load by default)

The animation was done quick and without any real attention to placement. Traditionally I'd use Illustrator for this then copy/paste as a shape layer into Photoshop. Or at the very least, I'd be using guides and aligning things better if drawing this in Photoshop.