At first, I started animating straight ahead to portray natural movement, then I was advised to look at my survival guide to understand each point in the image below
and this was the end result of the lines, with the in-betweens. I'm happy with this result.
Then I coloured it in and realised that I should have cleaned it up because of the black background in this example
(Gif didn't work properly so here's a link)
Using TVPaint for the first time was difficult until I quickly developed my knowledge of how each tool works, there were a few hiccups like the transform tool not working properly by moving my drawing when I'm about to use it and etc
I should have started the project off at a higher resolution and used bolder lines to make it less difficult to fill in and look sharper in the end result.
Here is the final animation that I quickly composed on after effects, then rendered on premier with a colour filter to boost up the saturation to pop out the colours.