Oookay, this time we are going to do wires and pipes.
For this one, all you need is a graphics package
which has airbrush tool. Of course, Photoshop is recommended since it has very nice channel features. (read: saved selections)

Start a new image, and make the following
selections (draw it to a new channel):

Now, airbrush some shadows and highlights
with the airbrush tool:

Using the airbrush, make the big pipe look like this:
(of course, you can use the line tool
but I prefer the airbrush)

Go to Quickmask mode (key Q) and aibrush some
faint selections over the pipes like this:

Go back to normal mode (key Q again) and add some
texurizer to the selection to make it look a bit worn.
(this one is optional, if you feel like not adding it
then don't.) Then you should have something like this:

The final touch, a red, blue and yellow thin wires,
just draw them by hand with a small airbrush.
Also, darken the wires from certain aras to add
some sense of depth.

There. Now we have 3 pipes and 2 wires.