Start with a scribbly mess
Then add some eyes and ears. Oh, it's a cat now!
It's a bit off to the side, so let's bring it more center. Fill in the part of the scribbles that will be the head/body, and erase those that are too far out
Keep working on the shape to get the proportions a bit better. The head is always important because that's like, a focal point usually
Oh right, cats need a tail. I always forget that. Also, maybe this will be a sad ghost so it's kind of different from the other.
Make the wispy bits nicer and add them as it seems fit. As long as they sort of taper, it doesn't really matter. I just go by what "looks right" for this stuff.
Now make the background dark and draw a lighter outline around the cat-ghost. This should be wispy in spots too. The eyes are white so they stand out more.
Clean up the image overall to make it not entirely sloppy.
Now I use one of those effect things to change all the colour at once. I decided to go with red for this one.
It's a little dull, so let's tweak the colours to make them contrast more. A few more minor changes to the face and I guess it's done!