I wish all aircraft manufacturers gave so much consideration to the "workplace" of a pilot.
I'd love to see:
The engineers set up a mockup of their cockpit in plain daylight outside. Then sit there from 05:00 LT in the morning and stay put for 8 hours. Do the same from 14:00 LT until 22:00.
Get your secretary to bring a cup of coffe every hour and inquire about your well-being every 20 minutes. (you will be amazed to find out how badly placed door surveillance can be.) Do the same and simulate the automatic door opening failed so one has to get out of the seat every 20 minutes or so without hitting aircraft controls.
Individual heating controls would be my #1. One always sits in the sun and the other freezes his feet off because A/C duct temp is 0degrees C.
Sun is a major issue all the time. A transparent possibly gray sunshade to even look through in approach without distortion and color changes.
Windows which are up do date and have no filaments but coating for the heating. No distortion on any window.
Previous posters pointed out how important sun shading is.
All windows heated to avoid freezing your outboard shoulder at night. Sun shades do the trick as well.
I'd rather have 6 EFIS screens in order to be able to monitor 2 status pages on systems independently.
Seats shall be electrically operated with manual backup. Should have enough travel to comfortably get in and out. Not to mention ergonomy of the seat itself. Eventually vented as in the luxury cars? Headrest. Reclinable to comfortable napping position.
Enough stowage. Try it out in a mockup once with the same stuff you carry when getting off a plane such as a carry on bag (crewbag) coat, hat, jacket, then try to hang it in the cockpit without getting in the way. Where does the hat fit? Where does your laptop go?
Waste bins Airbus style. Power outlet 12V.
Oxygen masks with long enough lines to reach over one seat at least - but make sure it doesn't get in the way. Place masks eventually overhead in order that nothing can drop into the mask compartment.
Headset plugs overhead so that the cable is out of the way. Seats built in a way that cables do not get stuck anywhere.
Controls which give limitations but I can oversteer if need be as described by Pilot DAR.
More in detail. Not an issue in recent designs but a thought: Parking brake setting and releasing from both positions. Steering always on both sides.
Interconnected flight controls (electric/electronic/mechanical). Auto throttle not auto thrust! Visible trim. Eventually a trim audio tone indicating trimming in one direction over x seconds. So you know what the autotrim is doing.
Overhead panel with switches in the system diagram (standard today).
Maybe more. If it is valuable you may PM me to get more ideas.
I assume that the handling of controls in normal and abnormal situations is not an issue and always has to be possible.