>>28393241. Use MikuMikuMoving or Blender. ALWAYS animate in 30 FPS.
2. Interpolation will become your best sexfriend, since you will be fucking A LOT with it. Arm IKs sort of simplify things, but you will still need interpolation for everything. Most models don't have arm IKs, so if you need, but I suppose it might be easier with IKs. The catch is unnatural arm bending (if you're asking for tips, you're presumably autistic enough to care), and limits are not a superb solution for that due to sudden snapping they introduce even in simple cases like supporting one's weight in a lotus position or giving a paizuri handjob. Also see:
https://archived.moe/e/thread/2790558/#2796182https://archived.moe/e/thread/2798100/#28038793. The most convenient way to rotate around the pole is by placing the center bone directly in the middle of the pole and only using it for horizontal rotation and some additional height control while using the groove to shift the relative position.
4. For adaptability purposes, I wouldn't advise using either of those to rotate along the X or Z axes instead of rotating the torso bones to maximum freedom. Sure, it's simpler for motion making, but since they act as pivots for the whole body and their location differs between models, that can lead to vast position differences, which is not good and can further complicate adaptation.
5. For complex movements of IK-controlled limbs (ex.: right leg kneepit hold in pic related distro video 0:58-1:02), you can turn off IKs momentarily and trace the path of the target bone(s) (in a leg's case, ankle) with IK placement, correcting the interpolation according to locus path or by using ikeno's Arc effect (or you go the dumb way and place keys every frame). For long segments (ex.: last part of the said video), best to just turn IKs off and bake IK chain positions at turn-off point (not before registering the state of leg bones with IKs enabled though).
