Fill the bottom of the tray with a double layer of pea gravel or a single layer of small pebbles. Shake the tray slightly to settle the material in the bottom.
Pour water into the tray until the gravel or pebbles are halfway submerged.
Set the cyclamen's planter on the gravel or pebbles. Add water as needed to maintain the original level, as the constant evaporation of the water keeps humidity at the appropriate level.
Mist the cyclamen daily during hot weather to lift the humidity even higher. Spritz the plant five or six times with a plant mister or atomizer to create a light layer of moisture on the leaves and stems.