when my kids were toddlers they were 'slapped' on the top of their hands and scolded, then put in timeout while it was explained what the discipline was for (which they had already been told repeatedly) this timeout lasted 1 minute for each year of age. This was not necessary very many times from me, or their mother.
As my kids have grown I have had to spank them a few times, very few. I have spanked them with my hand only; and never in anger. My son is 13 and my daughter is 6. They are both very well behaved and straight "a" students with no conduct problems at school. I am blessed because i was a knucklehead as a child. I believe also that consistent expectations of behavior and having my kids in church 3 times a week are the biggest factors in this.
FWIW a sgt, major that served under my dad was talking with me when i was about 16 yrs old. His kids were the best behaved, most respectful kids i had ever been around, 5 or 6 years younger than me. I asked him what the secret was to his kids being so good and successful. He said good people were made the same way as diamonds, with steady; even pressure. That has stuck with me all my life and it effects the way i deal with my kids.
My expectations and my attitude toward them never changes. If i have a bad day at work, i dont bring it home and have a short fuse with them. If i am in a great mood, like watching the VOLS win... i dont allow them to run around crazy or get away with things they would not otherwise be allowed to do. I keep an even keel with my kids and they always know what to expect from me, and what i expect from them. It seems to work very well, though i am definitely no expert at raising kids. Just sharing what has worked for me. Sorry for the long post.