Its easy as long as you have at least the top 5 contenders in every dragon opponents.in my case which i play from 6am - 11pm daily( thats 18 battles a day ) i usually get 12 - 15 materials daily.so that is way beyond the second craftable dragon.so i suggest you check the arena calculator and list the top contenders that you have and get them to epic form...when you face archon for example, you have to have at least divine, lacewing, morning glory, twiliglight or whatever dragon you have which are the top contenders.but if you dont have diamond and champs this is impossible.so disregard the dragons that are not in the top 5.dont feed them anyway you can use them in tournaments even if they are level 1.