I make a conscious effort to pronounce them differently, as well. I pronounce "you're" just as I would "you" with an 'r' at the end. I pronounce "your" to rhyme with "yore". Many, many, many people do not make the distinction. I must admit, however, that both often end up in "schwa" in rapid speech, if whichever word is not accented.
I also am careful to make "our" rhyme with "hour" rather than with "are".