This lady is probably the reason you're wearing skinny jeans right now...

Michelle Siwy heads up denim at Wildfox, which in other words means every festival It girl now has her Coachella wardrobe covered. We caught up with the first lady of California casual to pick her brains on what it takes to make it to the top.

Describe your typical working day. I typically wake up pretty early to walk my dog with a strong cup of coffee to gather my thoughts and ease into the day. I’m usually answering a mountain of e-mails from around the world that somehow accumulated over the six hours of sleep I try to get. While I am in LA, I am usually running in between various places like our sample room and the many denim wash facilities. Denim is so complicated and it takes a number of rounds to get the wash and fit perfect. Sometimes, as many as 13. At night is the only time I really have time to read and sketch up designs. I will often fall asleep with a pencil in my hand. Very silly but true!

What was your first job? My very, very first job was selling Avon when I was 13. I was an Avon lady! It was the only job I could legally have if my mother co-signed. I mainly sold my friends bubblegum or pineapple lip balm and body lotion.

Who inspires you? I admire strong women who have experienced adversity under the most dire of circumstances and prevailed unscathed, stronger without bitterness. I think of Tina Turner, a woman who had all odds against her and still did not lose faith.

What's the best advice you've ever been given? The best advice was being told to not try to please everyone. I think when you are new to the fashion business; it’s easy to take everyone and anyone’s word to heart.

Tell us about your path to the top… I started off college as a Nursing major. I started taking fashion illustration classes at RISD (Rhode Island School of Design) during summer break and then somehow I got a place at the Fashion Insitute of Technology (FIT) in New York - I was so excited! The move to NYC was the beginning of my dream. I knew it would be a very big deal to drop out of Nursing school for my mother, so I didn't tell her until the day before I was to arrive in NYC. I promised her that I would make something of myself. I took an opportunity to work for a store and I was immediately traveling all over the world to work with different factories. I was quickly moved into the denim department, just as premium denim started becoming popular. Most design students dream of working with "real" fashion like couture, which I do appreciate, but, for me having I love creating something beautiful and very wearable.

Which career achievement are you most proud of? I am really proud of being a pioneer in the skinny jean movement. I was the first American designer to offer them in a denim collection. I fought for it tooth and nail until they believed in it. If you can communicate your ideas and vision clearly with conviction, your chances of success multiply.

What did you buy with your first big pay cheque? A Chloe Paddington bag. 

What are your workwear wardrobe staples? A black blazer that can dress up tee shirts, an oversized white button down to wear with shorts or tucked into high-waisted skinnies, a cashmere cardigan that you can put on if it gets chilly and sneakers by Isabel Marant keep me comfortable but sophisticated.

What did you want to be when you were a child? I wanted to be a ballerina, but a car accident that left me disfigured most of my childhood put that idea on hold. I spent much of my youth in hospitals and either bed ridden, on crutches or in a wheelchair. My family would bring me sketchbooks and international fashion magazines every single week. I started drawing the things I’d see in magazines from Europe and the world which forced me to pay attention and appreciate detail.

We're always obsessing over our work/life balance – how do you manage it? I am often pulled in many directions during normal business hours, so it’s safe to say finishing work on time is non-existent. During crunch time for sampling, I won’t even think of going home until after 2am only to be up, dressed and ready by 7am. I will do whatever it takes to finish on time with no excuses. When I believe in something, I can’t be stopped.

How would your colleagues describe you? I’ve never thought about it but I think something like being friendlier and more down to earth than they expected. I hope!

What's your plan B? There really is no plan B. If fashion doesn’t work out for me, then my only hope would be to move to the Maldives, set up a stand and sell hand made friendship bracelets on the beach.

Head to wildfox.co.uk to check out Michelle's latest fashion offerings. Michelle Siwy is no longer affiliated with the Siwy Denim brand, and the denim products advertised by Wildfox are not produced by Siwy Denim. Looking for more career inspo? It's not too late to book tickets for Marie Claire's @ Work Live,

in association with Cointreau and Next. A one-day event on 23 April

2016, featuring advice, tips and inspiration from incredible speakers.