The value of bespoke trousers is often overlooked. The point of bespoke, of course, is to achieve a better fit. Off-the-rack garments are made from patterns that are meant to fit both everyone and no one in particular. Thus, if you hunt around enough, you can find something ready-made that fits “good enough,” but if you want to achieve that Platonic ideal of fit, you have to go bespoke.
This is obvious for jackets because the defects in a ready-made sport coat or suit are easily seen. It’s less obvious in trousers until you know where to look. Most men, for example, have pockets that gape and stick out like wings, while others have trousers that need to accommodate for one hip being higher than the other (not unlike asymmetrically sloping shoulders, incidentally). Additionally, individuals who stand with their hips pushed forward will have excess material at the front of their trousers, which will cause creases to form in the area that extends from the crotch to the knee. Others who slouch will have excess fabric at the back, which will create folds underneath the belt or form lines from the crotch to the end of the thigh. Men with bowed-legs and knocked-knees will have other fitting problems.
From my experience, the most common problems appear around the seat, which is the last place you want to look overly tight or baggy. Unfortunately, it can be difficult to examine how the seat truly fits without a three-way mirror. Twisting your back around to look at a mirror behind you will not work. I assume this is why most men think their trousers fit just fine; they’ve never taken a good look while standing in front of a three-way mirror.
Some of these issues can be addressed through an alterations tailor, assuming you find one that’s good enough, but many require changes at the pattern level, which means you have to go bespoke. The problem, of course, is the cost. Good bespoke trousers usually run about $500 and up, assuming you have decent tailors in your area (or at least some that visit). The price is expensive, but when I was looking at my closet the other day, seeing the wide array of trousers I’ve bought over the years, I realized that I only wear grey and brown, and only in solid colors (sometimes with a subtle, textured weave, like pick-and-pick, but rarely something actually patterned). Rather than buying a bunch of $150-250 trousers I rarely wear, it perhaps would have been better to get half of those made through a skilled bespoke tailor. Trading variety for perfection. Lesson learned.