In the manuals of corporate dress codes, a woman's handbag rarely merits a mention. Yet the purse a woman carries to work is much more than a place to hold a hairbrush. A purse can send a signal about its owner's character, says Monica Botkier, a New York-based handbag designer. 'The bag tells a lot,' she says. 'When I read a woman, I read her bag. It's a little Rorschach test.'

Striking a balance between style and organization is crucial to projecting an image of chic competence, says Ms. Botkier, who developed her signature Trigger bag when she was a fashion photographer seeking a roomy but stylish bag for her gear.

For Ms. Botkier, a work purse has to be generous enough to move items between the home and office without becoming unwieldy. There is a fine line, she says, between spacious and burdensome. An office handbag should be large enough for a set of ballet flats -- but not cavernous enough for a pair of heels; it might hold an iPad, but not a laptop.

A great work bag should be well-organized, Ms. Botkier says. She looks for purses with at least one outside pocket for her smartphone. A few internal pockets help keep small items like keys and pens off the bottom of the bag. As the mother of three small children who like to rummage through her purse, Ms. Botkier likes at least one internal pocket to have a zipper closure. 'They'll get into everything anyway, but the zipper helps,' she says.

While some precious purses might stay bundled in a dust bag, your office bag will see daily use and should be made of a durable skin like cowhide or lambskin. Cowhide is sturdy but can seem heavy; lambskin is supple and lighter but more fragile. Choose deeper colors to mask stains and weatherproof the bag according to the designer's directions, she cautions. 'Stay away from suedes,' she says. 'The matte surface picks up dirt and can rub and get nubby.'

It's hard to appear competent when fishing in the bottom of a purse, pulling out personal items in the middle of a conference table. So while unstructured hobo bags might be au courant, Ms. Botkier suggests carrying something with a slightly stiffer structure for the office.

A bag with a choice of straps or handles -- to wear across the body, hoist on a shoulder or dangle from a wrist -- gives commuters options.

While fashion might favor tassels, noisy hardware and large logos, Ms. Botkier suggests toning purses down for corporate culture -- though creative offices might be more forgiving of trends.

She suggests switching purses with the seasons. In spring, she likes lighter colors -- pink or mint this year -- and less bulky bags. 'I always think of cross-body straps for spring, so you can have your hands free.'

In autumn, she prefers rich colors, such as deep plums or emeralds, and a larger handbag, which can balance out the bulk of a heavy coat and offer room for a hat, scarves and gloves.

To ease the seasonal swap, or to switch bags for the weekend, Ms. Botkier keeps her makeup in pouches. A leather makeup bag helps prevent lipstick stains in a purse and could double as a clutch for party wear.

When carrying gym clothes, paper files and other items too large for a purse, Ms. Botkier carries a separate bag that doesn't conform to somber office dress codes and can be stashed under a desk. 'It can be anything from a luxe leather tote to a cute fabric in bright colors or leopard prints,' she says. 'And that's your fun tote. It's something a little extra.'

Launched the Botkier handbag line in 2003

Developed her signature Trigger handbag in 2003

Botkier is available at Nordstrom, Shopbop and Botkier.com

Monica Botkier, her first luxury collection, will be out in the fall