Okay first of all THIS IS NOT A TUTORIAL (cause I’m sure pixel artists would laugh at me), just an explanation of some sorts, but feel free (and I’m flattered if you do) to take it as reference if you find it helpful : )
I’ve been asked about those gifs that I made a while ago, and how I did them.
Basically I have little experience with gifs and pixel art, before this I still used MSpaint for them, but the Binary tool in SAI is wonderful, and MSpaint doesn’t have layers.
I hope this explanation doesn’t sound too confusing, I suck at explaining and, in english it’s harder, haha, but this is it:

  1. I picked the main palette I’d be using (hopefully no more than 2-3 “main” colors per character, in these cases, black-white, and black-white-green)
  2. For bouncy gifs, I only needed two main parts, body and scarf, cause they have separate movements. The body movement is only a couple pixels up and down. And the scarf is more complicated, since it’s more flowy (?).
  3. Then I made a layer for each base color, (body-black, body-white, body-green, scarf-black, scarf-white) etc.(try to use layer groups/folders), and then just worked on some lighting and shading on the bodies.
  4. Since they’re bouncy, the movement is super simple, it’s usually only 4 or 5 frames, and I just copy/pasted the layers, (body-black1, body-black2, 3, 4, etc, if you had 4 layers before, and your gif will use 5 frames, you’ll have 20 layers in total now) 
  5. Slightly altered the duplicates so they’d be 1 or 2 pixels taller/shorter. (WOW, s-such animation!), pay attention to those bits like hair or clothes, they have “inertia” (?)
  6. For the scarves, it was more complicated to get a natural-ish flow movement so I just experimented with some basic random lines and put them together quickly animated to see if they worked, and once I got a basic movement, started working on the pixelart of them.
  7. All this was done in SAI, but then (lol don’t laugh at me) once I had all the layers ready for each “frame” I just put them together one at a time and took screenshots of it, cropped them and used Jasc Animation Shop (a super basic gif making program) to put them together as a gif animation. :’D

I had to do lots of trial-and-error, seeing what worked best and what not, but that’s basically how I did it. Thanks to all those people who were interested and/or curious about this and sorry for responding so late, hehe. Hope it helps!