Well I said I would do them... and honestly I made these bases a couple of months ago, so please excuse the pictures. It's not that they are terrible, but they aren't cropped or really edited in any way. I also think I missed a couple of steps, but as they are pretty basic I am sure you will be fine.

Okay, so first off, my materials were pretty simple:

Clean Bases
Plasticard (I think I used the .060 size)
Wire Mesh or Aluminum Screen (taken out of an old window)
Glue (but of course)
Calthan Brown
Iyanden Darksun
Dheneb Stone
Astronomicon Grey
Macharius Orange
Chaos Black
Ogryn Flesh
Badab Black

Looks like I used more paints on the bases than I did on the actual models.

First off, I cut some simple random Squares out of Plasticard. I use a Paper Cutter I picked up at Business Depot. It isn't the type with the large arm that swings down, it uses a wheel cutter that actually scores the Plasticard and then I just fold it along the score to break it in half. I usually drag my knife blade across any seams that I intend to make on the base, this gives a nice little bevel and make the whole thing look that much more industial.



Next I glued down some sand. I actually use a mixture of a couple different sizes of Ballast Sand. The different sizes just give a couple of random rocks here and there. It picks up the Dry Brushing very well.



I primed it after that... not really anything special here



After that I Dry Brushed the stone with Calthan Brown, Iyanden Darksun and then Dheneb Stone. Of course each successive layer was lighter, but you already knew that.

Now this is where I missed a couple steps, and I apologize for that.

The Plasticard was painted with Astronomicon Grey and then given a couple Iyanden Darksun Stripes. To actually paint the hazard stripes, I always start with the lighter colour since the black (or darker colour) will usually easily cover the lighter one. So I started with the yellow stripes and then painted some black strips on angles across the yellow. Now you don't have to be too neat, and I suggest making the starting strip bigger than what you want it, and then trim it when you are done. When I was done, I just cleaned it up with some more Astronomicon Grey and there it was.



The rust was pretty easy, and it was something I adapted from a couple different forum users. I used a dome stippler brush, if you don't know what I mean here is the link.

First I stippled on some Calthan Brown, and then again lightly with Macharius Orange. Then I dabbed a little Ogryn Flesh Wash on those spots.

After that all I had to do was wash all the plasticard with Badab Black and the bases were done.



Okay, they weren't completely done. I had to clean up the rim with some Chaos Black and then put the models on them of course.



And there it is, nice and easy.

Now, if you don't want to go through the hassle and pain the actually make the bases, Mike (being as epic and ducky as he is) has made it all WAYYYYY easier for us:

Urban Rubble Bases

I know I will be getting a bucket load of these for my Eldar. Makes my job just that much easier