Almost every WordPress site we build these days has at least one custom post type, some have more than a lot.
I came across this post by Seth Stevenson that is a very good resource if you’re interested in how to use WordPress URLs to filter custom post types and their archive pages.
It starts out showing you how to use URLs like
…to display “gallery” custom posts that may be in the category “portraits” but then goes on to show you how to re-write some of these urls to make clean URLs with less query string values.
Well worth adding to your bookmarks!