1. Make at least 3 times as much dye as you think you'll need.
I had to stop and mix more dye 3 times yesterday, and wound up using nearly a quart of each color. I definitely need to mix a few quarts at a time rather than a pint.
2. Use at least 3 times as much plastic wrap as you think you'll need.
I thought I'd laid down plenty, but when I rolled the dyed yarn up to let it set for a few minutes, suddenly there was an enormous, vaguely pink puddle on my garage floor. Whoops. (It got all over my shoes, too, but those are my painting shoes anyway, so no big deal.) My new mantra is, "I will not be stingy with the glad wrap. I will not be stingy with the glad wrap."
3. Dye one kilo at a time, for the sake of your own sanity.
Here's something you may not know - a kilogram of yarn is a FUCKTON OF YARN. Each kilo formed a skein that was about 4 feet long, a foot wide, and about 3 inches thick. It is super hard to get even dye penetration through that much yarn. Because I was doing two kilos at once yesterday, I didn't have as much room as usual to sort of spread out the skein, exposing more layers to get more controlled dye application, so it took forever to get it through the whole dense mass. Doing one kilo at a time will mean more dyelots, but I think it will be better for my perfectionist brain, and who (besides crazy dyers like myself) buys more than a kilogram of yarn anyway? What the hell do you need 4600+ yards of sock yarn for!?
4. This stuff is freaking heavy. Dye on weekends when hubby is home.
Two kilos of yarn holds a lot of water/dye. Those things must have doubled or tripled in weight by the time I was done. I almost couldn't lift the rolled fibers into the steam pot. And speaking of the steam pot...
5. This stuff is freaking huge. Use the biggest pot you can find.
After I had wrestled the dyed fiber into a rolled bundle, I realized there was no chance that it was going to fit in the steamer pot I had purchased, even though said steamer pot was an enormous 3 gallon pot. The rolled bundle was at least a foot across, and while I could have stuffed it into the steamer pot, I was worried that having the plastic wrap in direct contact with the metal sides would melt it into the fiber. So hubby - who came home right as I was finishing up applying the dye and scared the bejeezus out of me because I was working in the garage - made a mad dash run to the grocery store with me. We wound up getting a 21 quart (5 1/4 gallon) stock pot, then sticking a strainer in the bottom to keep the yarn out of the water. Even then, it barely fit.
Despite these unexpected difficulties, the whole dye went really well, and the fibers are currently drying and looking fab-u-lous, even better than the test skeins I did. :)