To germinate, Drosophyllum seed must be fresh. Various forms of pre-germination treatment involving giberellic acid, boiling water, fire, scarification, and stratification have been suggested and tried, but I have found that if the seed is less than a few months old it will germinate well without special treatments. If you have old seed, you can try the tricks I mentioned, but don't hold your breath.
The soil medium should be a sandy peat mix; I like to include large aggregate materials like 1-cm chunks of pumice, perlite, or rocks in the soil too. The highly regarded carnivorous plant author Adrian Slack suggests slack-potting these plants, although of course he did not call it that!