Not sure what kind of racks you have but for some back-in parking might be easier than front-in. I try to lock one of the back tubes and wheel if possible.

I'm also a fan of the Sheldon Brown lockup strategy[1]. There's also a modified version that may be more secure[2].

[1] https://sheldonbrown.com/lock-strategy.html

[2] http://www.802bikeguy.com/2011/07/the-modified-sheldon-brown...