First foray into the forums

[Onaginoffegin]

Joseph,
I'll add one more thing — there are some fine tutorials on Youtube showing various techniques — some of which the other Joseph already pointed out — that can help you turn the sound of a midi orchestra into a real one.
After you watch these, you'll find that a lot of the work that goes into an orchestral piece comes after the piece is done compositionally such as editing the string and horn tracks so they start softly and slide into the note, putting in crescendos and decrescendos, etc.

Also the way you play chords can have an effect. For example, if you're playing a C chord, take the E out of the middle and place it an octave higher or lower.
Another effect is, once you've finished your string lines, take an oboe and place it one octave higher, and a flute one octave higher than that. See how that sounds.
As Joseph said, combine different sample libraries, play each string part separately — don't just copy and paste because they will lose the "human" feel, pan your tracks differently, and become familiar with the "humanize" function in your DAW, which is especially helpful in fattening up your drums.

Have fun!

Henry