I've recently had one of my personal nightmares come true: the shoes I bought online ended up being to small and I had already thrown away all the boxes and return stickers. :(
The problem started when I decided I wanted to get some Geox low-heel wedges for work that are summer-appropriate as well. I completely forgot that a European shoemaker's size 40 is more like a 9.5 in US size conversion, and not the size 10 that the retailer tells you. Not to mention, European shoes tend to run narrower than other manufacturers.
I've learned valuable lessons:
1) Try it on first: Because I have special concerns about the length and width of my uneven feet--one's longer than the other, while the shorter is wider than the longer one--I will no longer purchase shoes online. If I'm trying them on, I can go for a larger size or a wider model to make sure my foot is comfortable and the shoe looks good.
2) Save boxes and receipts. Even for brick-and-mortar stores, never throw receipts, bags, and boxes away. Try clothes on in the store or try them on first thing when you get back home if you're shy about trying things in dressing rooms. This way, you can make sure items fit well, and you still have a way to return items with all the documents and wrappings, if you need to.
3) Variety can mean quirks: Remember that manufacturers, country of origin, and particular designs have little strengths and weaknesses. In the global marketplace that we currently live and purchase in, there is a huge variety of options to chose from, and we must remember what pluses and minuses all these options can bring us! Hard to do, sometimes, but something to consider.
So what will I do with my two, brand-new Geox shoes? I will go to the nearby cobbler to see if he can lengthen the two pairs. If he can't, I'll go to a handy, nearby resale store and see what I can get for them.