I used to use organic cotton balls when I first started DIY RBAs. I have since found a new wicking material that wicks like nobody's business! Rayon! Now, don't think of that word like you think of rayon clothing because the 2 are not similar. I use 100% Cellulose. !00% man-made cotton.
When I used to use cotton and saw other's images, I always used too much. Not any more. With the CCr (Celulose Cotton/rayon), I stuff it in there and wicking is awesome! It's almost as if I can't screw it up. It always works no matter how I wick it.
Flavor is awesome and the vapor production is just so much better than with cotton. Of course, that's all subjective. But for me anyway, that's that way it is. Great improvement over cotton for wicking.
Check out the ending pages of this thread:
Rayon wick, better flow, flavor, saturation and Nic Hit!. Better yet, take the time to read the important parts of the entire thread (those would be the posts by JeremeyR

)
Let me know if you want to know more.
David