When to Buy
Seamstresses are often very busy, particularly from March to October. Many will need 6 weeks' notice or more, and may have to complete the work early, as they are accommodating so many clients in prom and summer wedding season. Calling for even just a consultation early will ensure your spot. Most dresses require alterations of some sort, bring your shoes to your fittings. Consult a seamstress if you need style changes that will require extra fabric when ordering a gown from any retailer, like adding panels, gussets or sleeves. Manufacturers sell the actual gown fabric by the meter, and it should be ordered with the gown. It's usually not available elsewhere, sometimes close matches can be found.
If you have particular tastes or a dream dress in mind, or concerns about finding the best silhouette for you, shop early!
Perhaps you want a simple or common style, are on a budget, or are expecting your size to change, or are waiting for a sale. Waiting until closer to the event, is not the best practice. While some shoppers get lucky, shops don't stock multiple sizes and colours of each dress to buy off the rack. Earlier shopping allows for more options, and for a seamstress to make style changes if needed.
Students post their prom selections starting in the fall, and others tend to find their options begin to dwindle trying to avoid getting same or similar. Shop early for dibs!