Jodie Fox loved shoes but could never find just the right pair in stores. So, during trips to China, Fox, then an advertising executive, carved out time to meet with a shoemaker, who created bespoke footwear according to Fox's designs. When Fox's friends began asking her to place orders for them based on their own designs, she knew she was onto something. In 2009, Fox co-founded Shoes of Prey, an e-commerce site that lets customers design shoes from heel to toe.

Shoes of Prey is part of a new breed of businesses that is taking product customization to the extreme. Thanks to technological advances, including 3-D modeling and printing, you can let customers design products from scratch. Meanwhile, the maker movement has inspired people to seek out DIY tools, says Rama Chorpash, director of product design at Parsons the New School for Design in New York City. "People will be happier with fewer things when they have a memory of making them," says Chorpash, who designs furniture and home accessories.

On the Shoes of Prey website, customers start by choosing from a selection of 16 basic women's shoe styles and 150 materials in various colors. Then, they select from a variety of options for the toe, sole, heel, accents, and other variables. The shoes, which range from $129 to $199, are then handmade in a factory in China and delivered to customers in four weeks.

The concept has been a hit with customers looking for footwear that's an expression of themselves, Fox says. Shoes of Prey, which is based in Sydney, Australia, has sold roughly 20,000 pairs of shoes in the past four years and raised $3 million in funding from U.S. and Australian investors. The company, which has almost 50 employees, recently opened a physical store in Sydney where customers can try on basic styles, see fabric swatches in person, and design shoes on iPads with help from in-store designers. Here, Jodie Fox and her co-founder (and ex-husband) Michael Fox offer their tips for successfully employing an open-ended design model. 

1. Invest in Tech, Slowly. Developing photo-realistic design software that's easy for customers to use has been key, Michael says. But sophisticated software is pricey. The Foxes launched their site with a basic 2-D design tool. After they began to generate sales, they invested in a souped-up 3-D tool, which took seven staff engineers and three consultants nine months to create. All told, they have plowed about $1 million into the tool, which is in its third iteration.

2. Embrace Lean Manufacturing. Finding a skilled manufacturer that won't break the bank is also crucial. The Foxes spent two months touring factories and commissioning test shoes before deciding on a facility in Guangzhou, China. The 15-employee factory uses lean manufacturing techniques, suchas stocking a minimal amount of material, that keep costs low. As a result, Shoesof Prey has a 50 percent gross margin on each pair.

3. Offer a Generous Return Policy. You might be tempted to adopt a strict return policy for custom-designed goods. Shoes of Prey has taken the opposite approach, allowing customers to return unworn shoes within 365 days of receiving them. The reasoning: Customers without design experience will feel more comfortable trying out the site if they know they have plenty of time to return their shoes, Michael says. So far, the site's return rate is a modest 16 percent.

4. Provide Stellar Customer Support. Customers can call, email, or chat online with Shoes of Prey's seven "customer happiness wonderpeople," each of whom has completed a rigorous shoe design training program. The online store also features more than 50 how-to videos on a variety of topics, including designing wedding shoes and working with snakeskin. The high-touch strategy is paying off: Eighty percent of customers have given the design process a rating of nine out of 10 or 10 out of 10.