Thanks Amine!
I first recorded the guitar part with a click track so that I could play with the other midi parts and and swap out various sounds to see how the arrangement would go with the guitar track.
I input the Midi data with a standard keyboard. I'm not that great of a keyboard player but I can usually do enough to bang out the part then edit the midi data to fix wrong notes, etc. I made a lot of use of the different articulations available in the orchestral library, where you can get different kinds of note attack, swells and various other effects that string players use, but using the appropriate articulation on each part. These articulations are controlled by hitting some other keyboard note ahead of the part you want to play. This really helps to make the orchestral parts to sound more realistic and less like sampled sounds that play the same way all the time. I worked a lot on the articulations to find just the right ones to use for various parts to get the effect I wanted from the different string parts.
I used Omnisphere for the vocal melody sound. I'm still not sure if I like it or not. I may re-record that part with a real female singer to see if I like it better. But I did like the Omniphere patch because it sounds kind of mystical even though you can tell that it's a sampled voice. I don't recall which patch that is in Omnisphere but I found it under human voices, "eeh" sound, or something like that.
Thanks again, --Jim