How do we discipline our 18 month old daughter? She has started throwing her toys or other items out of frustration or in an attempt to get our attention. She has also started slapping me. When she throws toys I will take that toy away and sternly tell her no. When she throws food, I try to ignore it or not give her a reaction because I believe she is seeking attention. When she hits, I grab her hand and sternly tell her "no hitting." None of these seem to be working. What is the best way to go about discipling at this age?