Then I have an application level CSS&JS that has everything generic in it. This is for a reasonably big app, so the overhead of having a single CSS/JS isn't insignificant - particularly when supporting mobile devices.
The other useful thing is a I as a dasherized version of the controller name and action to the body tag - as an id and a class respectively. So the body tag is something like
<body id='my-controller' class='show'>
These constructs are to be used sparingly -- you don't want to mash everything together too much -- but they're very handy when used right.