Sound Designing a pad synth

Have you ever searched an entire bank and you just can't find the sound you are looking for?

Well I'm at that point now and need to add a killer pad into my track. Right now I have the foundations and I'm rolling...but I just can't seem to find that pad I need.

SO I'm going to have to sound design this one and try my best.

Can someone assist me on how to start this? I'm a bit a lost, but if I can explain it would be a mid-high pad that has ambience and gives a sense of mystery to a dark track.

I'm thinking to start with the an LFO 1/1 and two OSC one for mid and the other for HIGH...and of course filtered and add some nice effects.

Well...if you can help that would be great...thanks