Do I need concept art to make 3d models?

Some artists sculpt their designs instead of drawing them, other go directly to edit mode. I like this phrase from this blog post: 

"The key thing when you making a concept in ZBrush is not to worry about tools, but be familiar with them because your mind must be free from anything else but the design of the character."

She uses ZBrush because she trust her sculpt skills more.

Concepts are made because in our mind things look amazing but blurry, sometimes in constant change. It's okay if you are not good at drawing, you are locking your design, to make a better thing out of it.

jack07 Are saying that I should sculpt my concept rather than draw it?  Or do you mean that a concept isn't required, and that regular reference images will work?

you can absolutely just use refence images for 3d art without drawing. When you are familiar enough to quickly do 3d blockouts on the stuff you want you start to see if that is going to work or not and move on. just like sketching in paper or photoshop. after that is just filling the blockout with details. this i can say from experience,  I do 3d concepts for descendent studios for their upcoming game descent underground and my drawing skills are very limited. :)  

williamatics More like look what makes you more comfortable. You can just use references, sculpt, draw concept or not use anything and just do it. You have to find out what makes it easier for you, what makes you worry less about your skills and focus more on your design.

Unless you are working with other people, a concept is only necessary if you need it. 

Photo bashing can also be a great way to concept for those of us who don’t have the drawing skills. There are lots of YouTube tutorials that cover it and it’s a pretty loose process so you can use whatever works best for you. And since it’s something no one will ever see, you don’t need to worry about it looking good as long as it gives you enough form to go on. 

Thank you for all your advice!