When shopping, I follow a single rule that when I am not sure whether to buy this or that, I'd let it go... no matter how unique or nice the quality. The presence of uncertainty made me realize that it's not worth going through the trouble, besides it's just shopping anyway, doesn't have to be brain-racking. If I see a pair of shoes (or something) that I really want then there's no turning back because sometimes when I come back it's gone.
Way back in college, I had Ethics as one of electives. In any other philosophy class that I had, there's a simple rule my professors would emphasize... (oh yeah even my Health teacher in High School would make kulit about this) "...don't act on a doubtful conscience, whenever you have doubts think about it several times...a hundred or even a million times first before you act on it..."
In general it's true. Both of my examples above will save us all from future trouble.
But what happens if emotions come into the scene? It's a lot harder than everyone thinks... yup, easier said than done!