Part of the journey is the end. And it looks like this might be the case for the great Tony Stark in the new Avengers: Endgame trailer. The trailer showcases his destroyed Mark 50 helmet when he turns it on to record a message for Pepper Potts.
I have an instructable on how to make this, and you can check it out here: https://www.instructables.com/id/AvengersEndgame-Iron-Man-Helmet/ . This took me about four days to make, but without the design process it was about three days. The original Mark 50 helmet design comes from Thingiverse, and was designed by Damask props. All that I did to the file was import it into Fusion 360 and take out the destroyed sections. I then added in the broken tech bits sticking out of the sides.
I recommend printing this at 110% scale or higher if you want it to fit onto your head.