So to answer some questions I said I would reply to:
When composing with VI, rarely will I compose 100% of the ideas that pops into my head, because I know that's not realistic and I'll end up fighting with the samples, so I prefer to work WITH the samples, and my ideas will revolve around what is available and sound most pleasing to me in a particular library. It could happen that a single articulation I like will trigger an entire piece because I know I can develop on that articulation without having to worry about it sounding good. Perhaps this kind of thing comes easier to me, I have no idea, but I am comfortable working like this. This would be similar to Beethoven using the harmonic notes of the french horn in his symphonies, he had a very limited amount of notes to work with, however, made great use of them as we know.
Often I'll have fun just trying things out in a library, just anything, like improvising between articulations instead of on a piano, and suddenly this sound is cool, or a combination or articulations I really dig, ok, we'll go with that, as silly as this. It's kind of working backwards maybe, but for me it works just as well, just a different order, and once you get going, the inspiration starts to pour in. As I said in another post, for me the most important aspect when writing with VSL is knowing your library, the better you know it the more enjoyable it will be for you, simply because it is like chess, there are over 9 million different possible positions after three moves each. There are over 288 billion different possible positions after four moves each. The number of distinct 40-move games is far greater than the number of electrons in the observable universe. This is also why I said, I could be using the same library and in 5 years will make better use of it simply because I experimented more with it. Another side of this is that you come up with ideas you would never have thought of from your head, and I guess that's where I can be more innovative sometimes. We aren't living in the 19th cent. anymore, so we need to adapt our inspirations with the tools available today to make the most of it. Sadly, there is a trend of this "out of the box" wish, and perhaps we are getting closer to this, especially with synchron, but I'd still work WITH the library for now or in part combination..
So that's one side.
I also sometimes will work with very specific ideas I have and figure out what articulations works best afterwards, like doing a mock up, which is a complete different way of working compared to the first way I described. For instant, I recently wrote a fairly long piece for which I completely did a 2 piano version first, unfortunatelly I temporarilly had to abandon it during the orchestration to work on synchron string demos, but during the orchestration I probably would of looked at what works best in the library. So it doesn't hurt to have some flexibilty and more importantly, not to get too attached to what you write.
Works with live orchestra.
I must confess that all of the pieces I've had played by real orchestras were done in VI first, some as VSL demos (like Mourning), some not, just for my pleasure, and always worked out very well making a score for the orchestra. It has never been a hurdle since I use the instruments in a pretty idiomatic way and if what you write is musical for each instrument and section, it will very likely be playable, of course some instruments like the harp, you can't write anything you want. But I've written some pretty wild demos over the years, and I know they would be very playable live, it's just a question of figuring out how to divide the parts to make it playable for each musician, that has never worried me, Ravel is my reference for this.
A few years ago I was asked by a Roumanian pianist to write a sort of concert piece for piano and orchestra based on a Roumanian folk theme, Rhapsodic Variations on Lie Ciocarlie For this I went more with a traditional approach, mainly because the piece revolved around playful passages and had enough material in my head.
I could probably go on about this for several pages, but this is just a glimps of how I like to work. Hope that it can be interesting or useful to some.