Very helpful indeed, unfortunately I didn't express my need properly: what I am looking for are tutorials on proper isometric perspective use of pixel art.
In other words: how do I take a real image or object, scale it down to pixel form, and finally mentally rotate it and skew it into an isometric way.
It's more of the mindset of the analysis of the objects than the actual technique of doing it.
With images: how do I effectively go from 1, to 2, to 3:
1.
http://prntscr.com/5rk1nf2.
http://prntscr.com/5rk1e73.
http://prntscr.com/5rk1j4