Something is to be noted about clothing when casting. Clothing can act as a barrier or wall between you and external forces. The lack of clothing as well as the presence of clothing makes a difference in some cases. I'm air, there are many things that I must do naked when learning them for the first time. I need to be in as much contact with my element as possible... and as being wind, it does have its quirks. I enjoy wearing shorts and tank tops because it makes connecting the the natural flow easier. On the contrary, being naked also makes you vulnerable. If there was a possibility that you could become harmed due to your cast then being clothed gives you an additional protection. Clothing in general is symbolic. If you associate a particular piece of material to have significant value/meaning to you, then it influences the art. jewelry or charms are also included here. There have been many occasions where I had to separate myself from my trinkets. If you wanted to wear a cloak because it helps with the ambiance of the ritual that is personal preference, but far from required. You'll find that as you grow more and more with the art that there is more of a feeling associated. . .
I hope this helped.