Kribensis

Caves, caves and more caves. Use a fine gravel or sand as substrate, the male and female will make shallow pits inside the cave and place the excess in a mound to make the cave mouth smaller.
Have a look at my tank in the gallery. After three days of having my pair they had started excavating the substrate.
Try and get an all ready established pair when purchasing, the females can be quite picky. Or a few females to one male, the males can become sex pests.

http://www.thinkfish.co.uk/forums/index.php/topic,2071.0.html

Take a look at this as well. It's basically a blog from day one of when my pair spawned.

http://www.thinkfish.co.uk/forums/index.php/topic,2115.0.html