the easy, non-obvious way. Did you know that I'm short? I'm not super short, but being 5'3.5" makes me too tall for petites and not quite tall enough for regular lengths. I hated having my pants hemmed because I hate the obvious look that you get when you just chop off the bottom and make a new hem. And I always buy jeans on sale so I never want to pay anyone else to hem them for me. I don't remember where online I first learned about this method, but it really works great. By keeping the original hem, you end up with jeans that look like you bought them that length.
First, figure out how much you need to cut off and measure it with your little hem ruler. I measured up 1-1/2", which means I was cutting off a total of 3". Be sure to double whatever your measurement is.
Then pin the heck out of it.
Next, sew all the way around the bottom. I used my zipper foot so that I could get as close to the hem as possible. Be sure to remove your pins as you go.
Stop to take a picture of a cute kid.
I finished mine off by serging off the extra and making a nice finished edge. If you don't have a serger, you could cut it off with scissors and use a zig-zag or overlocking stitch to finish the edge.
Here's the final project. You really can't tell they're hemmed unless you look really, really close.