Any question answered...

OK:

• D-lock through frame, rear wheel and round a street object.
  
• Cable loop through front wheel, one end through the eye of the other end, and then the free eyelet onto the d-lock.
  
  

Better:

• D-lock through frame, rear wheel and round a street object.
  
• Second smaller d-lock securing front wheel to down tube.
  
  

Even betterer:

• D-lock through frame, rear wheel and round a street object.
  
• Second d-lock through front wheel, down-tube and round a street object.
  
  

For my relatively utility bike I do the "OK" version above but only because it's never locked up anywhere for long without it being in my sight. For anything where I was leaving it for hours unattended on the street somewhere I'd be looking at "even betterer" as a minimum.

Have a look at the street object to check that it's secure:

• Using a street sign means your bike can be lifted over the top (they unbolt the sign on the post to do this).
  
• Thieves have been known to cut Sheffield stands and then put some tape around the cut to make them look fine to use. If you lock your bike to one of these stands then they can steal the bike without needing to make any noise cutting anything and the bike is gone in seconds.
  
  

Separate to the above consider security bolts to make it harder for the saddle/wheels/bars/etc to be stolen.

Don't use exactly the same place every day, try to have a few variations. Try to lock it up in a busy area although the thieves are quite happy to angle-grind anything even in a busy street.