You managed to secure two fulls with good feedback, so you're clearly doing something right. Congrats, you have some talent!
Voice is tricky as it, like all else in writing, is subjective. If there was a sure-fire right away to do it, every book would follow that and read the same.
Is it first person or third person? First person is easier to play with in terms of voice. I personally find third person sounds odd if it tries too hard to be different, unless the narrator is identifiable and known (by the author).