Think long and hard and have $2k-$3k set aside in case things go wrong. Find a mentor that breeds toy dogs and learn everything you can, be there when your mentor's dog whelps to get experience. Be prepared to be home 24/7 for the first few weeks if momma doesn't make it, because you will need to bottle feed around the clock. Know the lines well, back several generations, that your breeding pair came from. Have your dogs evaluated by a professional so that you know what their faults are and if they are breeding quality and a good match for one another.
I could never do it, I would be a basket case. Breeding toy dogs is not simple and NOT for the inexperienced or the faint of heart. We get a lot of stories around here like these:
http://www.yorkietalk.com/forums/bre...-my-story.html http://www.yorkietalk.com/forums/gen...ant-breed.html