Spencer Chase writes:

>... The little hog rings work surprisingly well but are a bit
> difficult to install correctly.  You have to punch a hole in just the
> right location and crimp the ring carefully without causing a lump.
> If you use an awl to make a hole, it will likely be off center as it
> follows the grain of the leather and will also split the leather
> making the connection weaker.

There were (and still are) special pliers made for just this purpose.
They have a pin/punch, crimping, and cutting parts to the pliers.
I once found an antique pair and had no idea what they were; I was
surprised when I finally found out.

They are still sold new, I believe.  A photo on the web of such pliers
is at  http://www.cutexsewingsupplies.com/catalog/2ba8_1_2038_1.JPG 
These pliers can cut the round leather belt cleanly, punch a hole for
the ring, and crimp it perfectly to join them together.

Rick Inzero
near Rochester, New York