For the most part I just tell them no and remove them from the situation if necessary. I can't think of a time when I had to put one of my kids on time outs at 12 months. I do spank lightly if they do something that can hurt them, such as running away from me into the road or trying to stick something in an outlet, but our house is pretty baby-proofed, so those situations don't happen very often. 12 months is a hard time as the child is starting to get old enough to have an opinion about what they want, but not really old enough to be able to tell you what they've decided yet. Hope this helps :)
Proud Mom to Megan Rose (7/31/02), Kylie Jeanne (5/22/04), Elizabeth Anne (1/8/06), and John Lee (8/13/07)
