I could spend hours trying to make the samples sound realistic and still end up with something that's not convincing.
However, if I upgraded to something more recent; I could probably come up with something convincing. When you have more articulations and more velocity layers to work with; it makes it easier to make something convincing.
This is where you're missing the real point: production. You'll learn a TON of very important and useful lessons and tricks by working as hard as you can to make even subpar samples sound convincing and good in your song. Even if you went out and purchased $20,000 worth of new sample libraries, you could still make it sound bad if you don't produce them right.
Making subpar samples sound convincing can be impossible sometimes though. I understand techniques that I can use to make them sound more realistic. But even when those techniques are applied; the end result is still not convincing. If I had a $20,000 library, it would probably have more articulations and velocity layers; allowing me to make more convincing arrangements. Sure I would still have to add expression; but it would be easier to make something convincing.
On real instruments, there are subtle sound variations depending on how hard or soft a note is played. Also, with real instruments, if you play a note twice in a row; the sound on each note is not exactly the same. Newer libraries emulate this with tons of velocity layers and round-robin samples.
So how can I emulate the subtle sound variations with one velocity layer and no round-robin samples? It's almost impossible.
How can I create convincing legato strings, without an advanced legato script? Again, it's almost impossible.
So if the end result isn't going to sound anywhere close to a real orchestra; why bother trying to make it sound real at all?
It's like I said in the OP. The Miroslav Philharmonik samples from Sampletank 3, lack the velocity layers and round-robins to be convincing. Sure you could try to make them sound real; but when you compare your attempts to a live orchestra, it will fall short.
Another way to say it:
When I mention "production" I'm talking about all of the things outside of the music notes you're doing. How is your EQ? How does your arrangement work (or not work)? Are there instruments fighting over the same frequencies and muddying up your mix? Is your panning good? Does it evolve as the piece does or at certain climatic points? What about your automation? Does your reverb/delay/FX chain help support the rises and falls in your piece? Do you have any tempo changes? Are your MIDI parts too quantized and therefore coming off like a machine, instead of emulating human players?
Your focus, in many of your replies, seems to be only focused on the sounds themselves instead of considering all of the production tricks and methods you could put into your pieces. These days we're not just composers, we're often arrangers, producers, mixers and doing our own mastering.
So, in short, start approaching your piece like an arranger would, then how a producer would, then like a mixer would and then finally like someone who's mastering would.
I do understand "production" related things like EQ and reverb. I also do try to make sure that no instruments are clashing.
But at the end of the day my samples are too weak to sound even close to a real orchestra.
I could add tempo changes and I could try to pull notes off the grid.
Perhaps I should just drop the goal of trying to sound like a real orchestra.