With hybrid lilies, I have used peat, perlite and vermiculite (each separately), and they all work.
Species, on the other hand, can be more picky in the moisture requirement, and it can be easy to incorporate to much water in the mix that encourage rot that wouldn't be a problem with hybrids. My solution is to use mostly perlite (rinsed to remove the flourine) and perhaps 10-20% raw sphagnum moss. Since the object is to keep the humidity high with as little free water as possible, the sphagnum acts as an easy moisture indicator. If there is not enough moisture, the dry sphagnum color will be noticeably lighter. (Then it's time to add s bit of water.) If there is condensation on the outside of the bag, that indicates too much water. Of course, once bulblets form, the vulnerable stage is past.
