What is good discipline for a 16 month old?

[Coltons mommy<3]

My son is almost 16 months old and I'm not sure what kind of discipline I should use for him. Lately he has learned the word "No" and if I tell him to stop doing something he will tell me "no" and/or hit. So sometimes I give him a swat on his butt. I don't want to do this all the time though. I don't want to be saying "no" to him all the time and swatting his butt all the time. I dont want him to be spoiled or bratty. So I want to solve this problem fast (if possible). Should I just keep doing what I am doing and keep on him? I've thought about Time-Out but I thought he may be too little for that. I'm not sure what I can do because he is still kind of little.

Any suggestions? What do YOU do with your 16 month old or toddler that i could do with my son?

Thanks!