There are numerous alternate ways to do this with many different types of labelling, plus you can use colours as well as stars. Stars could also be used to grade images, 1 being rejects, 2 being keepers, but if using your current labelling, "Show unrated files only" is the simplest method. Click on 'Star' drop down menu at top right of panels and you get that and other filtering options.
I didn't know that, thanks! However, it doesn't quite work in my situation as when the files are loaded, I have the models name etc filled in as the first step in my workflow. It could all be altered to suit of course but this is how I have come to work. Very methodical process else I invariably forget a step....
What happens with my files which aren't labelled as 'In Focus' is I keep them for a few short weeks and then I delete them after one final check.
I have used smart collections to search for all files which don't have 'In Focus'. This seems an unnecessary step though to create a collection for this and then delete it each time. This is why inverting the 'In Focus' selection is preferable.