This is the way I do juice (20L buckets): I take my measurements and make my adjustments while the juice is still in the bucket. Keep in mind that many (most?) juice buckets have been preadjusted by the vendor or distributor. Some even contain yeast already.
I keep records on each bucket individually. Then I get a 23L glass carboy, and fit it with a big funnel. I pour and splash some of the juice into the carboy to give me enough stirring room in the bucket for the next part...
Out of habit, for each 20L bucket I also add about 3 teaspoons of yeast nutrient, and half a teaspoon of yeast energizer. Mixed with this is 1/4 teaspoon of k-meta. I then stir this into the wine left in the bucket, aerating it like crazy while still cold. I prepare my yeast starter and put aside.
Then I pour in the juice into the funneled carboy from a good height, using a small pail so that lots of splashing happens in the carboy. Unless this is the lucky rare wine that gets to visit the barrel, I also add my favorite M+ toast french course oak chips to the mixture at this time. I then stir the must inside the carboy vigorously with the small end of the spoon. Then I loosely plug the carboy top, and leave it until morning.
The next morning I stir it some more, then when it settles I just pour the stirred yeast culture in and fit with an airlock. It's rare that I don't see signs of visible fermentation start within a couple hours. I let it ferment completely dry in the carboy (takes 4 to 7 days), and start stirring it every few days once the yeast starts to settle at the bottom. I leave it settle for the entire third week, and finally rack into a 19L (5 gallon) carboy with 1/4 teaspoon of k-meta added to the receiving carboy. There is no "secondary" fermentation. Sometimes, I'll add MLF culture depending on the wine, but I more roughly rack it at the 2 week interval in that case and add no k-meta.
I bulk age, so I don't worry about fining, filtering, degassing, etc.