mmmcrafts.blogspot.com streamlines her jeans to be skinny. I have at least one pair that need this treatment but am pensive about modifying jeans! I have avoided due to the specific thread, needle, and patience needed; but darn it she makes it seem easy; and I swear she's wearing my boots!
Turn old jeans into skinnies by laying a skinny pair on top of inside-out old jeans and tracing the skinny leg line with chalk onto the old jeans. Then sew a line down the chalk line, cut off the excess, hem up the bottoms if too long and you got a new pair of jeans!
I tried this and it actually worked out pretty well! It definitely looks best with jeans that are uniform in color. Faded or purposefully roughed jeans have more noticeable coloration on the side seems, which disappear from the knee down when you do this!