For a petite, learning how to hem is almost essential, unless you can hire a tailor or stick to petite brands only (but hey, even petite brands don't always provide the right length, right?). So last weekend I got to learn a bit how to do a simple hemming with a sewing machine at Inger's.
This is a Zara casual suit pants with side zipper, EU size XS. The material is stretchable cotton and polyester blend. It has nice side slits and industry-made invisible line at the hem, but for me it's too advanced to recreate the same, so I decide to do the simplest hemming, which is double fold and sewing together. Remember the material is stretchable, so when you sew make sure that you stretch the material as well, so the lines don't end up being too tight. I also suggest that you practice sewing some lines first if it's the first time you use the sewing machine, and do it with a supervisor! Or perhaps practice on some pants you don't mind “destroying accidentally” first, heehee!