Propagating riccia typically involves spore sowing as the primary method. Key factors for successful growth include maintaining high humidity, ensuring indirect light exposure, and using a well-draining soil medium. Special considerations should be taken to avoid water stagnation which may lead to rot. The general difficulty level is moderate but requires attention to moisture and light conditions. Steps for propagation: 1) Harvest spores from a mature riccia, 2) Prepare a tray with a sterile, moist growing medium, 3) Sow spores evenly across the surface, 4) Cover tray with clear plastic to retain humidity, 5) Place in a warm area with indirect light, 6) Keep soil moist with misting, 7) Gradually acclimate to normal conditions as plants establish.