yeah, i’d agree with out front of curtin house.
also, out front of city library/journal cafe on flinders lane. there’s bike racks there and always at least a few other bikes there. i’ve locked up there til the wee hours before.
I’d leave my steed in the underground carpark of the RACV club if you are near Bourke and Queen.
Access to public if you look like you know where you are going. Spots to lock your bike are near the lifts.
where would be the best in sydney cbd :S ive started a new job there and want to ride to work but ive been a but eek about locking my bike up any idea’s? i know this is for melb but it saves me from starting a new thread 
I know some people lock the bike up and take the front wheel with them. That way if someone breaks your lock they can’t ride off, and people will think somethings up if someone is wheeling a bike around missing a front wheel.
You shouldn’t lock you bike in the same place all the time as thieves can learn your schedule.
Use two locks if you are worried.
Most bike crime is opportunistic, two good locks and a lack of a front wheel is a damn good way to make sure your shit is safe from the average fingerbanging thief
PROTIP: Lock it up next to the full carbon with a $10 lock. Its not your bike they’ll steal.