Best Practise for clean looking animations?

[mp.simon@outlook.com]

Hi there!

I've been playing a little bit with spriter pro now and i was wondering:

What is the best practise for animating a character?
I've created a rough, basic humanoid shape with all the limbs separated like in every video tutorial i've seen so far.
The joints are also overlapping a little bit. Here is the combined humanoid: https://1drv.ms/u/s!ArYlbQR8de6_n1385AdTtQpLVFsU?e=zCarU3
 

In Spriter:
I edited the joints of every part, put it together on the canvas, added a bone for every skin and assigned each bone to the respective skin.
So what do i do now, to get a smooth animation and to make it look homogeneous? I realize that this is where the animator-know how starts, but my question has a reason.
Basically i would say i need to adjust the bones and the skins for every keyframe. more keyframes also means smoother animations, right?
So what i need to do is rotating bones, deforming bones and skins and work towards a natural looking animation, right? I feel like i am missing something fundamental.

Is there a special way to prepare your skins/sprites before putting it in Spriter?
Do the joints/overlapping bits need to be round, or have a certain length to make the process easier?

This stuff is new to me and apparently i am already having a hard time finding the ressources i need to learn the animation process for this kind of program.
i've read the manual of spriter but that doesn't tell me how to create/adjust my workflow.

EDIT:
is it smarter to use 2 bones for one limb (like the leg or the arm) instead of cutting the limb in 2 pieces (eg. lower arm and upper arm)?

To be precise i look for a solit method to animate the char without people noticing it consists of several pieces.  Maybe that's a better way to explain it?