Practice

The practice booth is in the next area right across from the shop.
 

Talk to the lady at the stand and a wooden dummy will appear in the middle of the wide-open ground. Press O right by it to go into sparring mode. In sparing mode, the dummy inherits the behavior of a regular thug.

While training, you get unlimited roulette orbs, which is good for testing new roulettes or just for the heck of it. You will not lose your health if you get hit as well. You can 'recover' your health by using a healing roulette or increase your enemy level here but it will return to normal the moment you leave the warm up room.