Having always worn my chinos without a crease, I was surprised when I heard this question for the first time. But soon, I realized that there are obviously several people who have wondered about this - should I wear a chino with or without creases? What is the standard way? IS there even an standard answer?
A chino trouser is a casual piece of clothing - irrespective of the fact that you wear it to your office on workdays, or you wear it dressed up with a jacket, dress shirt and a tie.
While there is no sartorial rule that prescribes that a chino should be worn with, or without, a crease, the general convention is to wear it totally flat - without a crease.
There is also a practical reason to wear a chino sans creases. Let me explain.
The chino fabric is comparatively stiffer than standard dress trouser fabrics like wool, wool blends or linen. As a result, the fall and drape of a chino is not as free - making it difficult to manage the clean lines of a creased trouser.
You will understand the effect of this stiffness once you notice the way a fresh chino acquires an s-shaped fold at the knee region once you wear it for a few minutes. This effect is magnified if there is a sharp crease in the chino. The visual effect is of shortened limbs - not good in my book.