Each time when you join the challenge you receive the free stamp for the next challenge. You can also buy extra digis.
I have printed out the free digi onto white card and coloured with copic, tria and distress markers and added punched butterfly. Layered onto red card which I embossed with Cuttlebug daisies. Layered all onto green card which I stamped with Stampin Up Stamp.
I was lucky to find this blog at the beginning of the challenges but you can still join in.