Sure hand centering is a good skill. ...kind of fun up to 10lbs or so. I am a big guy (200lbs) I can do it. But, when i get to 25+ pounds, it can be quite a struggle. Being lazy, I built a centering tool that I power with my left calf, which is far stronger than my arms. In fact, it is quite easy to push the clay right off the bat. I can wheel wedge with it.... push up with my left calf and push down on top with my hands.
Also, with the teflon roller, I don't have to put any water on the clay, though I do have to watch for clay build up on the roller. I got the teflon roller from a rolling pin I got from a garage sale. Clay is the universal adhesive, so it even sticks to teflon if the surface of the clay gets wet.