1. We shop in the same price range (since we work together and are, ergo, equally poor...) You don't realize how essential this point is until you see your shopping buddy pick up four YSL bags, three pairs of Loubs, two Roland Mouret dresses and you have... a partridge in a pear tree. By Zara. Which you really can't afford. Or imagine it's the other way round and you're holding armloads of designer goodies and staring at your friend, who's crushing the partridge in a death grip so you don't take it from her. Middle-class guilt, anyone?

2. We know each other's closets so intimately well, we can actually say stuff like "but you already own two forest-green bags of similar size and stature, they don't need another friend" or "omigod doesn't this look exactly like those Choos you've been wanting but at half the price?" 

3. Both of us have iPhones with data plans. Meaning that at any given moment, should the other party be stumped, we can do a covert emergency photo session in the changing room (or, er, in plain view of everyone else) and email blast girlfriends on the spot to ask for opinions. This function is also useful if you've been asked to shop on someone else's behalf, by the way. 

4. Since we shop together a lot, we can actually hold each other to the secret deals we make with God (or the devil...) that allow us to make that extravagant purchase. "Okay, if I buy this ridiculously expensive, totally unnecessary, have-to-have-it-anyway dress, I won't take taxis to work for a month." Or: "After this, no more shoes for three weeks/months/years/decades/centuries." And when necessary, the other party can also act as agent of God to waive the ban: "Okay, you can take a taxi today, but you have to extend your taxi ban for two more days at the end of the month."  Or more likely: "Okay, you can break the shoe ban early. But only if I'm allowed to break the bag ban!"

5. We have drastically different personal styles. If I had to boil it down, I'd say FashionGeek is more London-Milan (House-of-Holland neon-punk mixed in with the luxe knits of Italian fashion) while ShoeGeek is more NY-Paris (girly-edgy cocktail dresses by the armload and lots of monochrome basics, plus a little ghetto fab for good measure). You'd think this would be a roadblock in the shopping experience, but it's not, because we never fight over clothes! In college, my roommate and I had essentially the same aesthetic (if you can call super-low-rise jeans and slutty backless tops an "aesthetic") and that resulted in numerous duplicate purchases, which is not cool if you see each other every day and sometimes end up in exactly. The same. Outfit. Anyway, in the rare case we do spot something we both like, it's a first-come-first-right-of-refusal system with the understanding that whoever purchases the item must be prepared to loan it to the other. =)

Finding the perfect shopping buddy can be a lifelong process. I have plenty of friends whom I love and respect, both as friends and as fashionistas, but I simply cannot shop with them. That's why us Geeks have to stick together!

Image: NY Times (it's a partridge, in case you were wondering. Which you probably weren't.)