If you can put them on a sloping bed, that will help. Otherwise, amend your soil with equal parts compost and sand. The ideal is to have the bulb base sitting on a dry material such as sand or gravel, so that the roots reach through that layer into nutrient-rich soil. Set bulbs at a depth about twice the height of the bulb. If it is 3 inches tall, the top should be 6 inches underground.
Lilies are tall and narrow, so plant clusters of at least five.
More would be even better. If your bulbs never seem to come up, you could have a problem with mice or voles. Plant bulbs in a cage made of berry baskets or hardware cloth. Early summer is a great time to buy lilies. The bulbs are often at half price, and that's a good buy if they are firm with no sign of rot.