The Art of Not Being Seen
You know, the most important thing in a good heist is not getting caught. And by that, I mean, getting caught, but not by the cops, by the art critics.
So, step 3: learn to blend in. Wear a fedora, wear a trench coat, and for the love of all that's holy, learn to use a comb.
And if all else fails, just pretend you're a tourist. Who's a tourist? Everyone's a tourist!