If you're only sharing selfies on Instagram, you may need to re-think things.

Instagram is catching up to Facebook as the most popular social network in the world and millions of businesses are using Instagram in their marketing. It's important to build a brand, whether that's a business or yourself.

When I was visiting Hollywood I found an actress who is making her living now teaching people the importance of professional looking Insta photos and how to take them. Kali Cantrell saw an opportunity as Instagram began exploding in popularity. When casting directors search for the right actor for a certain role, many will review their Instagram and Twitter accounts to see how many followers they have before calling them in for a screen test. Cantrell, who operates @Instaphototours began teaching fellow actors how to build up a large following as well as how to take awesome Instagram photos. That goes, she says, for anyone in any industry.

"Whenever you interact or engage within Instagram, you build up a following and that ultimately provides credibility and it enhances anything that you want to do," she said. "Public speakers can benefit, real estate agents can benefit, doctors, law firms."

Sure enough if you search Instagram for people of a certain profession you'll find thousands who post photos every day. Hairstylists and fashion critics in particular often gain large numbers of followers.

"I always encourage everybody to build a brand for themselves because it adds credibility no matter what industry you're in."

Cantrell meets clients at a coffee shop on Melrose Place in West Hollywood. After discussing the importance of Instagram she takes clients on a walking photo shoot where she snaps hundreds of pictures, directing clients in how to pose, where to pose and details such as props and lighting.

"You don't have to be perfect on Instagram," she said. "All you have to do is capture a moment that reflects you."

The day I followed her class Meredith Riley Stewart (@meredithville) an actress with several screen credits, Toni-Robison May (@toekneero) and Courtney Ashton (@cocoyouloco) posed in front of buildings, on the street and in a cafe as Cantrell snapped photos as her husband Mike positioned a reflector to get just the right light.

After studying Instagram strategies Kali offered the following tips for anyone who wants to build a brand and attract new followers on Instagram:

"I always emphasize details, whether it be props or making sure your hair and makeup or outfit look good on camera."

"Make sure you look natural and you feel confident because no matter how you're feeling, it's going to come out on camera."

"If you're going to be taking smartphone photos: lighting. Make sure your lighting is on-point, that can make or break a photo."