I re-potted my Echeveria runyonii on 3/20/2012. It came out slightly off-center and I rather like it. I also love the way pale succulents look in terracotta pots.
I’ve been adding extra perlite to the “Cactus, Palm, and Succulent Mix” I bought (though only for some of my plants). Perlite is the white crunchy stuff that comes in potting soil. It helps with drainage, which is important for most succulents, to various extents. I started adding it with my Euphorbia suzannae, a plant particularly inclined to rot. When I remember add it, I put anywhere from one part succulent soil and one part perlite, to two parts soil and one part perlite. (I suspect also that there is less perlite already in the bottom of the bag of succulent mix than in the top.)
You should be able to pick up some perlite at your local hardware store or big box store, depending on the season. In the middle of January, I ended up getting it from a local greenhouse owner by bringing him an empty container and a few dollars. And, like most things, it’s also available online (though it’s a little expensive to ship).
Don’t let the people at the hardware store convince you that perlite and vermiculite are the same product—they’re not. They can be used for some of the same purposes, but but vermiculite actually retains water, which isn’t so great for succulents. (And I believe that vermiculite is used for rooting cuttings of some plants, for which perlite would not be as useful.)
Be careful when opening your container of perlite: in large quantities, rubbing against itself, it can make some nasty, sharp-particle dust. It should be fine as long as you don’t stick your face in it and there’s not a strong breeze.