if u go into a store put it infront of a window where u always can keep an eye on it iv had a bike stolen b4 and it sucks.....
Sitting by a window will honestly only give you a front row seat to your bike being stolen. If someone who actually knows how to pedal grabs your bike, by the time you start heading towards the door, your bike is gone.
I saw a friend's bike get stolen. It was literally a matter of seconds between the guy grabbing the bike and him being half way down the street.
There is no safe alternative to locking a bike up properly. If you don't have a lock, don't leave your bike. If you leave a bike unlocked using any number of tricks, don't complain when it gets stolen.