I always prepare the soup base with the followings:
Soup Base:
One whole chicken, remove skin and fat
Chinese Ham or bone
half of one catty of lean pork (depends on how much soup you want to prepare
Optional
Shreded Chinese Mushroom (to be added when the shark fin soup is ready, boil for 15 minutes)
What you could do is
1) Defroze the sharkfin
2) Sock in tap water for half day
3) Steam it until tender and cooked, put ginger and spring onion under (For dried product I normally steam it for 3 hours above)
Finally, put the shark fin in the soup base and boil for 30 minutes, add Chinese mushroom