Although I have been a Mac user for a couple of years, I have recently just learned of this good tip that can enhance your spotlight searches, you can seach for specific types of files, for example in your search box if you type:
This will then only search for the file type pdf.
Or if you wanted it search for files and applications that had been accessed today you could type in
Another example is you could search for anything created after a certain date, for this you would type:
I am always interested in feedback so feel free to add any comments, or you can mail me here, also if you would like to submit a quick tip with full credit and links back to your site then also feel free to contact me.