My old jeans needed some work. I took out my old hemming job and hemmed the legs properly. When I do this sort of hemming, I have at least 0.5-inch seam allowance, but stitch as closely as possible to the fold of the original hem. You can see what the inside of this procedure looks like here.
The advantage of my past laziness was that the original hem was in good shape. The jeans may be old and turning raggedy, but at least the hems look new!
I also had to patch for at least the second time the thigh area. Wanting to avoid having to do this again, I used a patch large enough to cover the entire inner-thigh area and then some.
If I could only find some reasonably-priced jeans that are dark washed, proportioned for petites with the large rear-small waist combo, and without any whiskering or pocket ornamentation, I wouldn't have to go through all this!