I generated a few character names by working on the same lines that Mervyn Peake thought along in "Ghormenghast" - characters with names like "Barquentine", "Steerpike", "Prunesquallor", et c. I'm sure this has leaked into Discworld somewhere along the line, and the principles are easy enough: putting together ideas and concepts not normally linked, or using slightly archaic older English nouns and attaching them to people.
Author Peter Tinniswood, now deceased, used a gazeteer of placenames in the North of England and used these for character names: indeed a place like Accrington Stanley deserves to be a Discworld name. "Reddish Bottoms" or "Gooseaargh" and many other also have a Discworld tinge to them!