Working the red carpet sans beau Joel Madden, the busy working mom showed off her itsy bitsy waistline in a silver gown less than eight months after giving birth to her second child.

Whether it’s motorcycle boots, a simple t-shirt or a sparkly dress, there’s just something about Nicole that makes everything she wears inherently boho.

We caught up with the designing mom Wednesday night at West Hollywood's Satine boutique, where she participated in an Earth Day Eve do-it-yourself craft station.

With the help of the Dasani Green Cap program and DIY expert Erica Domesek (pictured -- in green, of course -- with Richie at left), Richie made green crafts and offered us practical tips for staying environmentally friendly.

Starting at home, Richie says "at my house, we use recycled plates and cups. We avoid paper cups for coffee; we turn off our power when we're out of town."

The "we" would be her fiance Joel Madden and their kids, daughter Harlow and son Sparrow.

"Even unplugging your phone charger when you're not using it, little things like that are very important. The Earth is our home and we have to treat it with respect."

For the Richie-Maddens, Earth Day could even mean enjoying time outside. ...

"I consider myself pretty outdoorsy, so I'll probably go out and bask in the sun," she said of plans for her brood.

To green up playtime, Richie scored a recycled Satine tote bag with Harlow's name stamped on it, personalized with hearts and puppies, to use for her toddler ballet class.

Fashion fan Richie notes that sporting vintage is actually recycling.

"This is actually my newest vintage buy," she said of the pink kimono she wore over jeans, which could easily be accessorized for the red carpet.

Richie made a studded fleece cap, right, at the event with the help of Domesek, who was on hand supporting Dasani Green Cap's 100% recyclable PlantBottle.

Richie designs Winter Kate, a range of women's wear, as well as House of Harlow 1960, a jewelry line that will expand to bags and sunglasses in the coming season. Her second novel, still untitled, will hit shelves this summer.

2 Layering is the key to an easy and chic look. In my Winter Kate collection I've created pieces that are easy to wear. The right jacket with an amazing print can really make an outfit. Layering a waistcoat over a print blouse will suit anyone.

3 Nothing is against the rules when it comes to fashion. What was worn in the 60s and 70s can seem mad to us now, but the inspiration can be transferred to a modern look. Dress for yourself – that's how real style comes about.

4 Little things can change a whole outfit. I'm a jeans-and-T-shirt person, but I like to throw on cute shoes, jewellery and cover-ups for a splash of colour. You can pair a print dress with zebra-print platforms and statement jewellery for night.

5 It's good to go all out. I used to pillage my mom's closet, and my dad's costume designer made miniature versions of his looks for me. It's great to include costumes and dramatic vintage in your wardrobe.