Prepare yourself for chilly winter days and nights by snuggling up in this season's coziest design: the cocoon dress. A cousin to the trapeze and smock dresses, this silhouette has been around for decades. Notoriously difficult to pull off, the latest incarnations of this voluminous garment offer considerably more style than a sack, and are forgiving for all figures.

Recently seen on the runways of designers like Stella McCartney, Moschino, and Chloé, the cocoon dress is a favourite of fashionistas around the world, who appreciate its clean, simple lines. "All women can wear them because they are so forgiving," insists Erin Wahl, senior buyer for Aritzia.

The key here is length, Wahl continues: "Tall women don't want it too short, where you can't move your arms freely, and shorter women should ensure it's above the knee by one to two inches, otherwise it can work against your height. And always remember the look is about wearing one cocoon shape at a time and keeping the rest of the outfit simple."

Subtle tailoring, interesting necklines, frothy pleats, and ornate decorations make this season's cocoon dresses some of the most versatile, stylish, and comfortable pieces you can introduce into your wardrobe. With a quick shimmy over the head, you can literally cocoon yourself in instant style and comfort.

For anyone still dubious about pulling together this look, Wahl suggests pairing the dress with opaque tights and lace-up heeled shoes or ankle boots. Throw a boyfriend cardigan on top, and you're good to go. Those who are intimidated by the volume or just prefer a sleeker shape can add a belt worn at the actual waistline.

At Aritzia Base (1100 Robson Street), pieces like Lauren Moffatt's gold-trimmed black satin dress ($515) and Mint's silver frock with a jewelled scoop neck ($508) offer great examples of the use of elegant detail and fabrics.

The devil's in the details, and these dresses–while simple in shape–are hardly simple in design. The Lauren Moffatt dress, for example, uses subtle seams at the waistline to create definition without disrupting the flow of the dress. The Mint dress features an elbow-length sleeve and large pleats to create an airy quality that isn't generally associated with this dress shape.

The use of more formal fabrics and embellishments–such as jewels, semiprecious stones, and studs–is also a trend this season. "Dresses that would normally be associated with 'holiday' are now being worn every day," Wahl says. "Of course, they will also make great party dresses, but now you're getting more bang for your buck because you can wear them day and night."

If you're looking for something more casual, materials like polar fleece and stretch jersey provide the ultimate in comfort. Also at Aritzia, the Wednesday label offers a playful, sailor-inspired lilac jersey dress ($75).

For those wishing to add to their little-black-dress collection, Young, Fabulous & Broke has an adorable black polar-fleece dress ($175) with a close-fitting crew neck and slash front pockets. And perennial favourite Free People's cocoon offering comes in an elegant, scoop-necked black knit, with crocheted three-quarter bell sleeves along with matching crochet at the hem ($184).

Link: Aritzia official site