Hey just wanted to see if anyone can help improve my doors. The second one is the non-rusted version and the fourth is the one that I favor the most, but it still looks a bit off for me. After I get this right I plan on building a frame around it so it's not just the doors themselves. Any pointers or critiques are welcome. Thank you all ahead of time.

Gotta agree with Glustora, the third one looks the best out of the four.

The main problem with your door right now is one of color, not construction (the overall shape and look of the thing are both great). I don't get a sense of depth or grasp the idea that these doors are supposed to be metal, and part of that comes from a lack of proper shading. The “shadow” on the inner parts of the doors, for example, lack the contrast necessary to create the illusion of depth. The keypad is a great example of a depth illusion: the shading/coloring of the outer parts of the keypad make it look “sunken into” the door. (I can’t say I like that light shading at the “outer top” of the keypad, though.)

You’ve got a good base to work with here. If you work on creating both the illusion of depth where it should be and the sense that this door is made of metal, you’ll have a much better piece.