Well, that is a tricky question depending largely on your ideology. In general, people breed for two reasons, for the wonderful experience and to "create a better pet." What that means exactly varies from person to person. Many people breed towards certain appearances, and that is all well and good. I however, feeling that budgies of any mutation and coloration are beautiful in different ways, prefer to breed for a better nature. I would try to find sweet and easy going parents for laid back offspring, and fiesty and playful ones for higher energy pets. If you are also interested in breeding for personality, I recommend getting to know your hens. Think what personality traits a male could have that would temper their faults. If the hen is flighty, uptight or reserved, perhaps a relaxed, gentle or playful male would help their offspring to have more open and tame temperaments. If there is something you love about your hen, her activity level, her intelligence or sweetness, try to match a male with similar desirable traits.
If it is color you are concerned with, it depends largely on the color you hope to arrive at. Any coupling of birds can end in beautiful offspring, and the more unusual the parents look, the more unusual and varied the offspring look. I have seen two unusual parents raise five chicks that look completely different to each other! If this appeals, then try to find males that are striking, unusual and look nothing like Storm and Dragon.