This question was already asked million times, but I do have an issue with the very simple solution of adding
/blog/%postname% to the permalink structure.
I've installed several custom post types an d I use the Custom Post Type Permalinks plugin to have a permalink structure of
example.com/cpt_name/parent_cat/child_cat/postname. This works really well. Now I wanted to add
/blog/ to all my blog posts (default WordPress Post post type). So I added
/blog/%postname% to my permalink structure and it works well. That was pretty simple...
BUT I now checked the permalink for my custom post types. They are
example.com/blog/cpt_name/parent_cat/child_cat/postname now, which is definitely not what I waned... Do you know a solution that should work in this case?