Well polly, I wouldn't want to trivialise your predicament, but it sounds like they did you a favour when they nicked your first bike.

, sorry I am only joking.
I don't think there is any easy solution, what I have noticed is that most bike theft is opportunist - but there are professional bike thieves who will specifically target "nice" bikes, generally speaking if they decide they are going to take it they will.
Apart from making your bike less visually attractive it is wise to choose the location where you will leave it wisely. IE a suitably public place where many people pass by, and preferably where other people also leave their bikes. Lots of people coming and going makes thieves nervous.
If you have quick release wheels and saddle this is beneficial. remove the front wheel and place it next to the back wheel then feed your lock through both wheels and the frame of the bike when securing it to somthing really solid or heavy. Remove your saddle and take it with you, This will make stealing your bike a lot more hassle than it is to steal sombody elses.
Never leave your bike in a public location overnight, whether it is locked or not, as the extra security afforded by your considered approach diminishes in the hours of darkness, and the longer it is left the higher the chance of thieves taking notice of it.
Do you not have specific areas where bike usage is provided for with secure structures and cameras?