While all plants need sunlight to stimulate flowering, you need to strike the right balance between light exposure and stressful growth conditions for snake plants to bloom.
Flowering is an energy-intensive task, so place your snake plant in sun-lit areas. Constant light exposure is ideal, but three to four hours of direct sunlight will also work.
Ensure slow and steady transitions of light and temperature to avoid shocking the plant. For better results, move plants outside full-time once it's consistently over 50 degrees F.
Watering the plants only when the soil is dry can also induce flowering. Generally, this means twice every month in the summer, and at an even lower frequency during the cold.
Allowing the plant to remain root-bound, a state where roots become overcrowded, so they stop growing and begin to flower. Switch pots for bigger sizes every five to seven years.
After the blooms fade, trim the flower spike down to the base, as the plant won't rebloom from the stalk. This way, it sends up a new stalk the next time it's ready to flower.