If your seeds aren't sprouting at all or significant amounts are not sprouting, they may not be fresh or may have been stored improperly. A lengthy stay in a hot warehouse or even an overly warm kitchen cabinet may be the problem.
Be sure the seeds have soaked long enough, and that they've been kept moist but well drained. Dry seeds won't sprout.
Sprouts prefer temperatures between 55 and 70 degrees Fahrenheit. Temperatures outside of that range can cause sprouting to stop altogether.
Sprouts need air to grow. Keep them in the open with good air circulation or they may die.
The jar or tray that holds the seeds must be cleaned well between crops to avoid spoilage. Keep the batch well drained. Leaving sprouts sitting in a puddle of water is sure to cause spoiling. If a batch spoils, sterilize the equipment before starting the next batch.