As with most studio strobes there are very few factors that control the effect or "look" of the light, certainly with a ringflash...
distance to subject
subject to background
modifier or diffusion
using a ringflash in its intended position, shoot thru, my basic rule of thumb is to shoot parallel to subject, stay centered (shoot at the middle of subject) and dont change distance to subject for consistency.
the simplest hardest on camera flash there is, just like your basketball coach said... practice, practice, practice..
shot with a ringflash below...