You don't need a racer back crop top, paired with an athletic shirt slashed with vents and made of a material that actually neutralizes the smell of your body odour turning it into jasmine potpourri. Although potpourri is nice and I do own my fair share of racer backs.
It's great to feel good and confident with one's appearance. This isn't a condemnation of that. What I am actually pointing to is the consumer culture that has permeated yoga. I had a conversation with a woman recently who said, "I'd like to go but I don't have any yoga clothes." Yoga clothes?! Oh me, oh my.
I know it's paramount to be comfortable during yoga practice - to have freedom to bend and move - and yes, there are definitely certain kinds of clothing that are better suited than others. Wearing chinos and a blouse and practicing yoga doesn't offer the best range of movement, although I did have a woman in one of my classes recently wearing a blouse and chinos and she rocked her asanas like she was covered in lycra.
Yoga already needs enough demystifying as not being a contortionist cult. Let's take away the added pressure of having to wear certain threads.
You can come as you are. Sweat pants, tights, a t-shirt, a tank. You don't need to go out and spend money to look the part because there is no part to play. Yoga comes from within and it is already within you whether you've stepped onto the mat or not. No amount of high-octane super seamed pants will make you more of a yogi or help you to uncover your true nature.
You can bend and move, sweat and let go, just as you are. Sure, if you want the pants, wear the pants - that's neither here nor there. The pants are really beside the point.
What's important is that there's no special outfit, no right mat, no particular brand, that makes you more of a yogi. The most important thing to wear to yoga is a smile on your face and your heart on your sleeve. These two things will help you go deeper into your practice than any silver laced fabric ever will.