Now you know what I feed, so now what about how much I feed...
I feed Clover, my relatively young and growing ryukin, several times a day. I'm aiming for about 3% of his body weight, which for him means about 3 grams of food each day. I'd say he eats about 7-8 cubes of Repashy Soilent Green each day. I try to only give him 1 or 2 cubes at a time, and space the feedings out as evenly as possible throughout the day. The cubes are about 1 cm cubed. In addition, he also occasionally gets the frozen bloodworms and Saki-Hikari pellets mentioned above, but I don't count these towards the goal of 3%.
Callisto, my broadtail ryukin, is a couple years older than Clover and she also has swim-bladder problems. So I try to feed her a minimum of food to avoid aggravating her swim-bladder function even more. For her I'm aiming for 1% of her body weight in food each day, which means about 1 gram of food. She eats only 3-4 cubes of Repashy Soilent Green each day, and she also gets bloodworms and Saki-Hikari a few times a week.
Through the years my goldfish feeding regimen has continually changed; I think (and hope!) for the better. I certainly know more about good goldfish nutrition than I did a few years ago, and I'm still learning more each day! So I'm sure that given enough time, my feeding practices will continue to evolve. For now this regimen is working great for my fish.