Hey, that's a start--sounds kind of like my setup in a way (I've got a yard and a couple engine tracks, with industrial tracks in between.)
Here's a shot of my industrial switching area:
As you can see, there is a runaround track in the middle, with three sidings (one loops off to the left, the other two parallel the mainline.) The curves are kind of sharp for the modern era (that curve at far left is 12" radius HO) but the area is smaller than yours (2x3 for the industrial area, plus 1x4 for the foreground yard.) An 18" curve wouldn't be out of line for modern industrial tracks though.
For your own, it helps to have an idea of what sort of industries you want to serve--smaller industries would work better if you want to have a few customers in a small space. Good easy-to-model customers would include things like junkyards, warehouses of various sorts, printing houses or newspapers, small fuel facilities (all you need is a hose and a small tank) or small lumber yards.
To simulate moving traffic, sometimes more than one switching area, with some running room in between them, might be needed.