I have hand raised 3 baby budgie's and what I have done is the following
I keep them wrapped in a face cloth that I change at every feeding ( I wrap them up like a baby)
When I am done feeding I set them in a little container and fold another face cloth over them and leave the face cloth open by thier heads
I always hold them in thier face cloth until they fall asleep and feed them again when they holler
I always wash thier little butts with warm water and always wash thier little beaks after eating
I feed them sort of how much they want to eat with an eye dropper and baby bird food mixed with warm water to the derections on the bag
And as they got older they would come out of the face cloth and start standing etc and then it is time to play things by ear and when they got feathers and could stand I tried offerind seeds soaked in water to them mixed with the baby bird food on my fingers so they learn to peck at seeds
This is when it becomes hard to get them to start eating seeds and off the eye dropper and not being rocked to sleep in my hand after a feeding and n ot be wrapped either
I still have one little one who is over a year old that loves being wrapped in a face cloth and held in my hand and rocked to sleep chemocat