I used a block of wood with a smaller block on top of that, setting my AEBS on top. This then provides a lot of space for air to flow around most of the bottom of the AEBS, which seems to keep it a little cooler.
get a couple perforated bricks, lay them face-down beside each other and then rest your Capsule on top of them. bricks make good heat sinks, so i have discovered. be sure to get the perforated ones (with the pre-drilled holes).