A quick way to tell if a guy or gal has his/her look together: check the pant fit from the back. (Style checking can be fun!) Most of us only see ourselves from the front; the world gets the full vista. A saggy or too-tight pant seat isn’t what you want the world to see.
For both men and women: Most pants are cut for a “normal” seat. To find out if your seat is “normal” or not, check the fit of your pant in a three-way mirror. A flat seat will cause your pants to sag in the back. On the other hand, well-developed gluts (a larger tush) make pants tight across the seat—and splay out pockets. Or worse, from the full back view it looks like you are walking around with a wedgey all day. Not comfortable for you or the person walking in back of you.
If your pant seat sags, a good tailor can fix it. And when buying a new pair, get a size smaller than your waist then let out the waist (an inexpensive proposition.) If you have a larger than “normal” seat, buy pants the next size up, making sure the pockets are smooth. Then alter the waist to fit. If you get a larger size for your full seat or thigh, you might need to do some tailoring of the crotch and waist (you will drop some serious change to fix these.) Better to find a manufacturer that cuts for a full seat and thigh.
“Smooth” is the operative word for a well tailored pant—smooth in the front at the crotch (no camel feet drag lines … those diagonal wrinkles radiating out from the too-tight crotch, or as disturbing, the bunching of fabric that looks like you have a full diaper under there.) Smooth from the back view—no seam hiding in your crack, or fabric cupping under your tush, (jeans need to cup under your derriere, not a tailored pant.) The back of the pant needs to be absolutely smooth—no “crinkles” or folds of fabric either diagonally or horizontally. From the side view the pant fabric needs to drop in a straight line from the fullest crest of your tush to the hem.
If you happen to find a manufacturer that cuts for your body, shout hallelujah and buy as many as possible.