I don't have an answer, but there's a bunch of information on grafting roses. Some good videos too. I know some of the people in the conifer forum are into grafting too, and could probably steer you in the right direction.

People do some grafting of tomatoes. This would be inexpensive and one could see one's results quickly. I do not know if what you learn this way is useful when grafting trees and such.

Do apples, they are very forgiving.