The following is excerpted from "A Plantsman’s Guide to Lilies", a really good book by the well-known lily expert, Michael Jefferson-Brown, who has grown them all.
Picking the spot, and preparing the soil: Once you've determined that the lily is winter-hardy in your region, consider your soil. As for the soil itself, most lilies enjoy soil that is rich and "woodsy", which means somewhat acidic. If your soil is alkaline, you should attempt to change it if possible. (Rhododendron and azalea food will help.) Two species lilies, in particular, simply insist on acidic soil (L. speciosum and L. auratum) but others are more tolerant. Martagon and the old Tiger Lily are fine with almost any soil. The number one requirement for all lilies is good drainage. (Only the Leopard Lily is an exception here.) Most wild lilies come from very leafy mountain hillsides, where low growth shades the lily’s roots, but allows the flowers to bloom in full sun. That sort of environment also ensures plenty of moisture, but complete, perfect drainage. No standing water, please! I like to plant lilies in partial shade between shrubs, and along treelines. Of course, some, like Tiger Lilies, are magnificent right out in the open.
"When you’re ready to plant, take the time to prepare the soil at least 10 inches deep. Dig it thoroughly, remove the rocks, and mix in some peat moss. Even though you’re not going to plant your bulbs that deeply, the worked up soil will help them for years. The soil at the very top is also very important, since ‘stem rooting’ above the bulb is just as important to many species as the roots at the bottom of the bulb."
Planting the Bulbs: “Bulbs are probably best planted with twice their own depth of soil over their noses. That means most all lily bulbs should have about 4 in. of soil above the bulb. As for spacing, tough plants like The Leopard Lily, Tiger Lily, and Martagon Lily will quickly make the area their own; they need space to flex their muscles, (spread) so give them plenty of room, spacing them at least 12 to 15” apart.”
Mulching and feeding: “Lilies revel in mulches. They enjoy the insulating layer over their roots as well as the fresh root run for the stem roots and extra feed that is going to be provided as the mulch rots. If you can manage two mulches, one in late spring and another in mid summer will do a world of good. Pure peat is ok, but lack nourishment. Well-made compost is best. These two times are also good for feeding. The type of fertilizer to pick is one of those recommended for tomatoes or potatoes, often higher in potash and phosphorus than nitrogen.”
Watering: “Lilies are not fond of having their leaves splashed with water and dirt. In fact, good soil structure and mulching should maintain health even through dry periods. However, if you water, water the ground and not the lily, and do a good, thorough soaking job of it.”
Staking: “Grown with success, some tall lilies will need support. If you use stakes, be sure not to pierce the bulb when you plunge the supports into the ground!”