There is nothing easier in alterations than tapering (IMO), yet I see so many people wearing bungled pants. I wonder, if you are tapering the pants yourself, have you paid attention to these three basic tips?
The first tip is obvious (I hope). You really want to avoid that look of an upside down triangle or a carrot. Those of us who have a larger build do well with pants bottoms that are straight in line (or a slight bell) with our hips. A nice break for dress pants will have a measurement of 12"-15" around; whereas the skinny cut will measure about 7"-8" around (that's quite close to the ankle).
The most likely the cause of the twisted seats and legs I've seen in self-tapered pants is due to someone starting at a point on the outside and inside seams and stitching both front and back together. Taper from the back.
This means you have to take apart the legs and take in the seam allowance from the back legs.
On the BACK inside leg, mark your new seam line.
Pin the front leg seam line (where there is a fold from the original seam)
to the new marked line. This is where you will stitch your new seam line.
If you keep the three tips in mind, tapering your own pants will be fairly simple. Well, with those few tips in mind, I wish you success and inspiration in all you do, today and always!
PS: Here is where you can find a quick guide to download FREE for tapering tips.