You can go to all of the best yoga classes, learn all of the best yoga poses and do all kinds of other things that are supposedly going to make you really good at yoga but the fact of the matter is that at a certain point the kinds of clothes that you are wearing would play a role in your eventual success which is basically why you should consider what proper yoga attire is and ensure without a shadow of a doubt that you would conform to these standards which are there for a good reason which you are going to understand quite clearly once all has been said and is now out of the way.
The thing about yoga is that it requires you to be in awkward positions for extended periods of time. This is because of the fact that you need to be able to stretch your body, and some yoga poses are specially designed to allow you to get the best results possible. If you are wearing tight clothes then you are not following standards set by Marianne Wells Yoga School. Tight clothing can restrict your movement as well as the overall range of motion that you might be capable of at this current point in time.
Loose clothing is great since it allows you to move more freely. You can get into all of the best poses if you are wearing loose enough clothing. Don’t wear anything too baggy though. A robe would be too much of a good thing since all of that extra cloth is going to get in your way, so get something that is loose but still somewhat form fitting at least to a certain reasonable extent.