Punching a speed bag without the purpose being rhythm, but for the purpose of timing and accuracy. Punching a speed bag with legs in neutral position(no left or right lead being apparent). It really forces you to perfect your punching technique. I found if you have to push through the bag to get it to bounce right I was using the wrong technique. But when I used the right technique I was able to maintain my form. The overall benefit to this unorthodox use of a speed bag is improved punching form, technique, and potentially better sparring skill.