1) Easing and spacing. Alright, this is like, the backing principle of how people animate. Easing is the acceleration and deceleration of all movements. You don't want to suddenly start a movement and then stop it or have it go at the same constant speed. So, you'd want to start of with smaller movements, and then get larger and larger, then at the end of the movement ease it off with smaller and smaller movements. Like this kinda:
/ = frame
- = pixel movement
Of course you don't want to go exactly like this, but that's just the basic gist of it. Of course different movements have different spacings. A faster movement would start off fast and have bigger spaces between each frame.
2) Stiffness. Something you don't want. They way to get rid of it? Try to move every joint in every frame possible, even if its a tiny little pixel movement. Now of course some stiffness in certain situations is alright, but generally we don't want that, so try to move every joint enough, paired with easing and proper spacing to get a smooth feel to it. It will take a bit to get used to, trust me it took a while for me.
3) Choppyness. This works itself out as you get better kind of, since it has to do with easing and stiffness. Basically, don't suddenly move things or make things suddenly appear, stop, then move again, cause it will just look....blah.
4) Shakyness. Another DO NOT WANT. This will probably occur when you are trying to make things not stiff by moving every joint. When doing this, watch the onion skin (the grey shadow left behind every frame). Make sure to not move it in a sudden other direction, even a little bit, it will look shaky, so just watch out for it and edit if you need to.
5) Editing. If you need to edit a frame you've already made, click the frame you want to edit, move stuff around to your liking, and then click the next frame button (if you use pivot 3 it will do it automaticly when you select another frame). Make sure to go back and use this often is something doesn't feel right.
6) Flow. You'll probably get into this as you get better, but flow is basically how well your movements go into the next one and so on. As you get used to movements, you'll figure how to make them flow. Use the onion skin for this, it'll be really helpful.
Your ideas look tutorial'd from some youtube videos but that is pretty much how everyone starts. Keep it up and try to get the basics as listed above before you do long animations.