My main hobby - art

While I do have an attachment to PPT, my main hobby over the years has always been art, mainly pixel art
Here's just a couple of examples that I made in recent years (the dryad girl is actually an example of "textmode" art., but still sorta counts)

That's really cool! 
I like them all and am wondering how could I implement the second one from the top for a PPT game that gives a character so many different faces...!
The textmode art is something I tried and could never muster, so hats off to you.
How long - on average - does it take you to create a picture?