It happens that the buckle has a straight shape and does not repeat the bend of the strap on the arm. For example,
Someone does not bother at all, but I like it better when the buckle is on the strap. So, if you have a buckle made of plastic material such as silver, bronze or stainless steel, then you can try to change its bend yourself. ATTENTION! On fragile materials such as damascene steel not to use!
The buckle must be tightly clamped. It can be a vice or 2 pancakes athletic bar)
Do not forget to put a softening layer between the holding device and the buckle (for example, pieces of thick leather), so as not to scratch the buckle. Yes, and on the protruding part of the buckle you have to put something on. After all, not all buckles give in to the pressure of the palm. Some will have to knock with a hammer!
Start gently tapping with a hammer, gently bending the buckle. Probably, in the process will have to preempt the clamp.
In the end, you get this result!