If you've seen Sheldon Browns method then you've seen the proper way...but there is one thing that can improve upon his method, and that is to remove the front wheel and place it alongside the rear locking both wheels, frame and bike rack with one U lock. You can then add a thick armored cable lock for hassle purpose only.

If you look at the Cervelo, those Zipp wheels are expensive, a thief would be very happy to cut the cable and take the front wheel.

Personally if I had a expensive bike and was commuting to work or to school and was worried about it...well then I could afford a used bike or a WallyWorld bike and take that instead and leave the good bike at home, but that's me.

By the way, the above film of man sawing the rim of a bike IS NOT Sheldons Brown method for locking a bike, his method locks the rim AND the seat tube together. Now that same person would have to hack saw the seat tube making the bike useless except for parts.