put your wipers on , swith off engine/ignition when wipers are half way across screen...... lift blades and place an old curtain right scross screen and put blades back...... works every time
I let the drivers side blade get nearly to the drivers side edge before stopping it. Then I tuck a good stiff flattened corrugated box behind the blades. That arrangement doesn't cover right across to the passenger side but stands up to wind better here, and will manage a few soakings before it need replacing.
In the old days when car doors had proper handles I had a cut down tarpaulin (part of an old canvas lorry sheet) that I put across the screen and then tied the corners back to the door handles, but you can't do that with these modern flush handles...