bleachwhiteforums

DUMMIES

Red Dummy: It boosts your Attack and Your Health, also gives you experience like 2500/sec.
Blue Dummy (Reiatsu Transmitter): It boosts your Reiatsu Power/Pressure, also giving you the same experience.
Defence Machine: It boosts defence, increases health too. Same experience.
Training Dummy (Reiatsu Shooter): The fastest way to train Reiatsu Power, but increases only it (doesn't give any kind of experience).

Other Ways

Concentrate Reiatsu: Fast way to increase Reiatsu Power (only it too, doesn't give any kind of experience), but you can't have any percent of Fatigue, or maximum 99% because if you have more, it won't work.
Killing Hollows: It will only give you a LITTLE BIT of experience, Not useful, but is a type of training (Experience Only).