
Hi Ali,
Have you thought of putting that special rubber spike stuff along tops of all your fencing, gates and garden walls to prevent "comfortable" access to anyone trying to climb over to the rear of your house? (Carpet grippers at a push -

) Additionally, have a word with your neighbours to see if they can have their bins put into a lockable storage area so they can't be used to ease access to your property.
You could also try the anti-burglar paint (don't know the correct name for it) - stuff that makes things too slippery to climb or grip onto and badly stains clothing etc of any intruders. It's also worth adding sensor operated security lighting too ;)
Are your patio doors like regular French doors? I have reinforced double glazed French doors (outside glass pane explodes out onto anyone trying to break in, inner pane stays intact and procedure causes a helluva explosive bang as a warning) with added security deadbolts top and bottom. We do have an alarm as well to be fair but have not needed Thank God to have any of our safety measures put to the test but as our garden is large, fully walled, not overlooked and inaccessible from the front or side of the house we are very conscious about how secluded it could be - i.e. I'm a worry wart :D
HTH, Teri :)