"What should I wear?"

It's a question for the ages -- ranking right up there with "What is the meaning of life?" "What, exactly, is the story with Donald Trump's hair?" And, of course, "Does this outfit make my butt look big?"

For the last 365 days, Sheena Matheiken has taken away the guesswork from at least one of those queries. For one year, the New Yorker by way of India pledged to wear the same little black dress -- Every. Single. Day -- as part of The Uniform Project, her way of combining fashion, sustainability, and philanthropy.

It's served as a way to raise awareness of The Akanksha Foundation, a grassroots nonprofit that brings education to children living in Indian slums. So far, Matheiken's efforts have raised nearly $77,000 -- enough to send over 200 kids to school.

Adding in the sustainable element, she says, was a natural.

"I already shopped vintage and thrift-store stuff for years, so this exercise was more about formalizing that side of things," Matheiken tells StyleList. "It was more about showing that style can be very individual, and you don't have to follow fast trends. It was trying to bring that sense of creativity and individuality back into fashion."

So who better to give tips on how to diversify our own closets -- making the clothing we already have work harder for us.

StyleList quizzed Matheiken on her fashion takeaways a few days before May 1, the one-year anniversary of the very first day she donned Eliza Starbuck's black dress, which is designed to be worn both frontward and backward and as an open tunic (there were actually seven identical styles she could rotate).

"I never actually felt like I was wearing the same thing every day," says Matheiken. "Every day looks completely different. The looks make me feel like different characters, personalities."

When you flip through Matheiken's daily outfit postings -- she explains her 15 favorite outfits in the gallery below -- sometimes it's hard to believe the dress is always the same.

Matheiken stocked StyleList with tips for making clothes look consistently different -- even if you've been wearing them for a year straight. But now that she's worn that same style daily for a year, will she be retiring it to the Dry Cleaning Hall of Fame?

"I'll definitely wear it again," she says. "It's a good dress."

Tip 1: Find yourself. "The most important thing is to really feel comfortable and confident about playing a little bit. A lot of people forget that [fashion] can become a really easy and fun source of expression and, instead, people get very upset and stressed out about it. That attitude shift is the first thing that will help you start wearing things you thought you wouldn't normally have been able to pull off."

Tip 2: Shop your closet. "There are so many things in your closet that are just sitting there buried and completely forgotten. There are many things you can do in terms of layering -- little things you can add to change a silhouette, like a belt, or adding layers underneath a dress or over it -- that can completely change a look. And, very often, it's something that's already in your wardrobe. You don't need to buy new things. Just by throwing around a few things in different permutations, you can create a very different look."

Tip 3: Always accessorize. "You have to realize what is it that you like. Are you a scarf person? Are you a belt person? What are the things you're naturally drawn to? Expand on that and start playing with them."

Tip 4: Keep it simple. "It's interesting when you give yourself a creative constraint how much more creative you tend to become. Having these limitations was actually helpful and made me be more creative and push my own boundaries. For me, it was easier to get ready in the morning because you already had your base piece. So, then it was just a question of building off of it. I never had to wake up and go, 'Oh, no, what am I wearing today?' It was just a question of reinventing that thing."

For more information on The Uniform Project and to learn how to donate to the cause and purchase the dress worn by Matheiken, visit TheUniformProject.com.

THE YEAR IN DRESSES: SEE EACH OF MATHEIKEN'S LOOKS