Thinking, even during the roll of a touch and go, is important. Of course preplanning is good, and changing configuration on the go is not so good, but if you've decided to do it, it's worth practicing properly. In particular, once you have hold of the flap knob, feel for it's shape, and mentally confirm it is the flap knob before you move it. It's not so vital on a 152, but does get important when flying an RG. Complicated, I know, but one must master it!