Lilies are simply gorgeous. One single stalk with numerous blossoms, or multiple lilies in a lovely arrangement; these flowers deserve every bit of attention. That is why it is worthwhile to nurture your lilies well. In a vase lilies can blossom for at least 10 days, or more. So please take good care of your lilies. Here's how to do it.

Lilies are best transported into their original packaging, preferably at a low temperature. Once you've unwrapped them, begin by cutting the stem-ends at a slant. This will increase the surface area for water absorption. Ideally, the cut should be approximately 1 to 1,5 cm.
The vase should be cleaned well before use. When you have filled the vase with clean water, you may add a floral preservative to the water. If you do not use a floral preservative, please remember to replace the water in the vase daily and to recut the stems frequently. Of course, the water should be refilled regularly. Please replace the water when it becomes cloudy.
When arranging the lilies in the vase, it is important that the lower leaves are removed. Make sure lowermost leaves are not in the water, since this will cause bacterial growth, making the lilies wilt faster.
Lilies do not like direct sunlight; this too will accelerate wilting.

Summary:
	cut the lilies at a slant
	use a clean vase
	always use fresh water
	remove lower leaves
	never put lilies in direct sunlight

If you observe the above, you will enjoy your lilies for a surprisingly long time.

There is one minor point to a blooming lily: the pollen may cause stains on fabrics. This can be prevented by letting the pollen dry first before brushing it off. Instead of brushing, the pollen can be removed by using adhesive tape. Any remaining spots will disappear over time through sunlight. Important: never use water on pollen.

Source: Paauw Lilies