Don't get too hung up about flying a 'proper' curcuit (im talking PFLs here) I tend to fly quite close downwind the field then make a curved, constant aspect approach with the landing spot nailed in the right spot in the windscreen - it it goes up in the screen - turn in tighter or lose some drag . If it goes down, either extend, fishtail, slip or add more flaps. I'm a glider pilot too and this is the method I was taught. The high-low key point thing never worked for me and I used 'my' method on test with good results.
That said things can still go wrong - I remember floating nearly the whole lenth of a 1000m runway after arriving just right over the numbers off a flapless glide approach in a Katana on a sweltering 85C day - the bloody thing just would not go down!
Best of luck - believe me after the Nav/diversion it will seen like a walk in the park!
Kingy
