How do you plan a funeral if the deceased is being cremated?

The same way you would if their final disposition was a full-body burial, or another form of disposition. It changes nothing. 

You can have any combination of services you'd like, then follow with cremation. So, if you wanted to have a full traditional service with a viewing, if you wanted or needed embalming; you could have all those things. Then, for final disposition, you could proceed with cremation. If you are working with a funeral home, the only thing that would change is the possible need for a casket. If you choose a casket that will be cremated with your loved one, you’ll probably want to stick to something made of wood instead of metal, but you could also use a rental casket. People cringe when they first hear about rental caskets, but it's really a very reasonable and respectable choice. They are generally an oak casket with an inner lining which is removed, with the body, for the cremation process. The outer casket can then be used for someone else.

The arrangement conference looks the exact same rather someone is being cremated or buried. The only difference will be a discussion concerning the method of disposition. If the deceased and or their family want a public viewing of the deceased body they

will be embalmed and showcased as desired (preferably and most economically in a rental casket). If there is to be no viewing the deceased will be cremated and the ashes and perhaps photos present at the memorial.

FYI - A funeral is considered to be when the body of the deceased is present. A memorial/ memorial service takes place when there is no body present.