For the cockatiels I use parakeet seed mixture, mixed at least with two different mixture, and I offer in times pellets. But I prefer still seeds since pellets are actually not good choice for cockatiels or budgies. Millet, hamp, etc... I can't translate everything.
Salad, carrot, potatoe (not very often), corn, apple... Sometimes I offer boiled spaghetti which is good and soft to throw up for chicks and every one of my tiels love it. Seeds are available daily and there is usually something fresh with them. I also give boiled egg with crushed shells for the breeding pairs and sometimes to others.
I use three different eggfood types. One is just normal, one contains fruit pieces and one contains little fishes and shrimps.
My african grey gets more fruits but also seeds. Mostly he gets what our family eats because he usually stays in his stand in our living room so he gets "goodies" (fruits, vegetables) mostly straight from hand.
I give grit only 4-5 times per year to avoid over eating and crop problems. This is one of the things that the world has very strong opinions. One says that you must give grit every day, one says that never give grit... And I'm somewhere in between.