I feed a wild finch seed mix with millets, canary seed, shelled sunflower and thistle in addition to lots of fresh produce and Roudybush.
Real hookbill mixes in my experience go more than half to waste. My cockatiels, for whatever reason, don't know how to crack the larger seeds. They won't even touch sunflower in the shell, but I feel it's still valuable in the diet. They accept it husked, as it comes in my mix.
I no longer have cockatiels.