Shop
Sarees
 the best place to buy them is dadar. the place is buzzing 12 months a year. good shops to buy sarees are dadar emporium, lazaree, and roopsangam. you can buy almost everything a woman needs in eastern dadar at the benaras silk house on n c kelkar road and ranade road.
Atria mall
One of the nicest, best maintained malls in the city. For upscale there's Mango, Nine West, Aldo, Promod, Guess, La Senza all sold at slightly inflated prices in India. There's also your regular Nike, Reebok, Levi's, along with some cheaper local brands. Be sure to check out the Rolls Royce dealership next door.
Phoenix Mall
Phoenix Mall is one of the largest, most popular malls in Mumbai. You can find international designers and brands from Burberry to Guess, Nike, Zara, Body Shop, etc to local brands and Indian designers. Check their website for the store listing. It can get extremely crowded on weekends. Also has a multiplex, food court, supermarket, restaurants, pubs, and even a nightclub. You can easily kill an entire day here if you choose.
Central
At the site of Crossroads, what used to be Mumbai's first mall. Nothing to write home about.
Shirts
 reasonable priced shirts at adacks near sena bhavan.