I’ve recently begun to explain to my students how I choose the order of their scales by using the Circle of Fifths.  Basically, I just told them that C is zero accidentals (I don’t show them the circle) and that every Perfect 5th up from C adds a sharp and every Perfect 5th down from C adds a flat.  When they finish learning a scale, I ask them what the next key would be and make them use this technique to figure it out.  Periodically, I ask them, “What key would have 5 sharps?” or “What key would have 3 flats?” etc.  This further cements the concept in their mind. 

I remember when I was a student and my teacher showed me the circle…it didn’t make much sense to me at the time, so I just disregarded it.  However, when several of my students recently told me that they’ve been using my scale order technique to remember key signatures for their theory test , I figured the Circle of Fifths was doing more good than I thought. 

I’ve recently found several good theory worksheets for teaching the Circle of Fifths and for giving students the opportunity to draw the corresponding key signatures around the circle.

Worksheet for identifying the key by the number of sharps and flats.  (Susan Paradis’ site)

Worksheet for identifying the key by the key signature AND drawing in the key signature

Bass Clef Circle of 5ths (delineates sharp keys, flat keys, and enharmonic keys)

Treble Clef Circle of 5ths (delineates sharp keys, flat keys, and enharmonic keys)