Whether it's compiling naughty-or-nice lists, party organising, or prepping your travel plans, the holidays can lead to craziness and time-crunches galore. So let us save you a little outfit-assembling effort by offering four outstanding apparel options in today's penultimate edition of Answers! for the year and decade. No matter if you're lusting after Taylor Momsen's out-of-this-world outerwear or Sienna Miller's lazy day attire, we've got all the information you'll need to achieve these ensembles lickity-split! After all, they say a stitch in time saves nine, but with a little help from your Who What Wear editors, getting these celebrity-endorsed looks will be as easy as one, two, three!

Sienna Miller
Spotted late last week during a shopping spree in New York's Soho neighbourhood, Sienna Miller looked effortless in Acid Pull On Jeggings ($60) and the Big and Small Stripe Shirt ($55) from Topshop, paired with Rupert Sanderson's Joyce White Patent Oxfords ($635). Be sure to try Repetto's Zizi Femme Lace-Ups ($265) for a more economical alternative to her white brogues and a borrowed-from-the-boys blazer. Though Miller's Twenty8Twelve Joia Flannel Jacket ($499) is a worthy investment, Alice + Olivia's Eon Blazer ($396) is a similarly androgynous, superb selection. Lastly, toss a burgundy bag over your arm-the star's Prada Saffiano + Tessuto Tote ($1450) is a brilliant buy, but we think Botkier's Cooper Convertible Hobo ($595) is also a smart option-for the perfectly appointed holiday shopping final result!

Daisy Lowe
Model and former GOTM Daisy Lowe was spotted wearing a chic and sheer Dior Jane Dress ($15,990, 310.859.4700) from the French fashion house's Resort 2010 collection to the London unveiling of the John Galliano-designed holiday display at Claridge's hotel. (Yes, even Christmas trees can be uber-stylish in the hands of a master!) The British beauty looked on-trend in unbasic black; try Nanette Lepore's Love Triangle Lace Dress ($458) with your go-to opaque tights and favourite classic clutch. If you want to truly mimic Lowe's lovely look, make sure that you slip into a chic shoe selection like Anne Klein's Qiara Lace-Up Shootie ($89) and you'll be a party-ready frock star!

Rachel Zoe
A handful of inquiring readers sent us requests regarding the always-stylish Rachel Zoe's errand-running outfit-and for good reason! Seen here doing a little browsing on Robertson Boulevard in Los Angeles, Zoe was wearing an enviable off-duty ensemble, comprised of a Current/Elliott Biker Jacket ($288) in Overcast Destroyed and an extra-long and slouchy Alexander Wang Cowl Back Jersey T-shirt ($85). Though she rounded out her look with Chanel's two-tone round frames and classic carryall, we recommend trying Ralph Lauren's Round Sunglasses ($375) and ASOS' Chain Detail Slouch Bag ($136) for look-a-like alternatives. Just slip into a pair of Deena & Ozzy Suede Over The Knee Boots ($148) or Stuart Weitzman Suede Thigh High Bootsicon ($675), which are a bit more budget-friendly than Zoe's Casadei Suede Triple Platform Over-The-Knee Boots ($1300, 505.461.9880), and layer on a dazzlingly printed scarf, like this Rachel Zoe for QVC Paisley Border Crinkle Scarf ($40), and you'll project an impeccable rendition of the stylist's panache!

Taylor Momsen
During the past fortnight, we saw our inboxes positively inundated with Taylor Momsen-related queries, and we are perfectly happy to oblige those emails with some answers! While exiting the It's On with Alexa Chung studio, the Gossip Girl was wearing an array of desirable vintage duds such as her army shirt and jacket with fur trim. Though we can't get you her exact gritty garments, we can direct you to some almost-identical alternatives. Elizabeth and James' Safari Shirt ($265) is an ideal khaki button-up option, while PRPS' Military Jacket with Fur Trim Collar ($595) or Topshop's Fur Padded Parka ($160) will have you covered when it comes to coats. Just add a little feminine flourish with a pair of garter-belt style stockings, such as Wolford's Tabea Tights ($58) or Henry Holland for Pretty Polly's Mock Stocking Tights ($17), your favourite heavy-metal black bag, and a great pair boots and you'll be strutting in Momsen's signature rocker style in no time at all!

Photo of Sienna Miller, from Splash; Photo of Daisy Lowe, from Getty Images; Photo of Rachel Zoe, from x17; Taylor Momsen, from INF.