Your best luck will be to cross like with like. Cross trumpets with trumpets, orientals with orientals, Asiatics with Asiatics. Orienpets are the result of wide crosses between oriental and trumpet lilies and are generally not very fertile.
Like daylilies, lilies can be diploid, tetraploid, or weird things in between (triploid, polyploid... difficult to work with). Forget about Black Beauty, that one is a mule, so to speak.
If you want to be sure of the parentage, you must protect your cross with a foil cap.
Lilies are generally self sterile, so make sure you use different cultivars.
Well, in a nutshell, this is just a bit of starting information.
