Dendrobium Keiki growth - what now!?

[andrewfox1887]

My dendrobium upin king serenade has new roots growing up the stem. I did some research and found they are called keikis and can be cut off to form new plants, but I'm not sure what the next steps are! Where is the best place to cut the new plant off? What size pot is best and what is the recommended potting mix for this type of orchid? Any advice would be appreciated. I've attached photos to give a better idea of what I'm working with.