Pat, if you have light soil, one idea would be to actually plant your lily bulbs a little bit deeper than recommended, this will help delay emergence in spring (I wouldn't recommend this for heavy soil).
Also planting on top of a slope (if you have one) helps to ease the effects of spring frost and so could planting near the base of a large tree. Although planting near a tree is probably not suitable for trumpets as they would lean a bit much, but some orienpets can handle this reasonable well in my experience, it depends on the cultivar.
Also you could try to pick a place that has a bit of shade in early spring when the sun is low on the sky, but receives more full sun in the summer. Behind a large stone would work well.
And if you have a lot of snow, it could be reasonable to pile up some extra over the lilies as an additional 'mulch'.
