Cheap, easy to make, and flexible game/dungeon master screen for use in tabletop RPGs.

Step 1: Materials

You will need:
Corrugated Plastic Sheet - For this technique to work, it will need to be the kind illustrated here, with the fixed divisions. Corrugated cardboard can also be used but will not be nearly as strong.
This also needs to be at least as wide and high as desired to make things easier. Mine started as a 74x100cm sheet, enough for 2-3 screens.

Ruler - Preferably large enough to measure board's height.

Craft Blade - To cut sheet to size.

Plastic Paper Pockets - For placing GM/DM notes. I have used A5 here, purchased from Daiso.

Double Sided Tape - To afix the paper pockets to the plastic.

Step 2: Cutting to Size

Next, decide on your desired dimensions for the screen. Mine here is approximately 24cm high and I left it as 100cm wide.

After deciding, mark and cut the board horizontally.

Step 3: Cutting the Hinges

This is where the benefits of this type of board comes in.

Divide the width of the board into 3 and find the approximate notch of the corrugation and mark them.

Cut at these two marks through the first layer of plastic but not through the second. This will allow the second layer of plastic to act as a joint.

Next, pick one side and cut through the same way on the next notch further out on one side.

As the notches should be approximately the thickness of the board, this will allow the sides to fold over nice and compactly.

Step 4: Affix Plastic Paper Pockets and Place Notes

Affix as many paper pockets as desired for your GM/DM notes using double sided tape.

By using these pockets, content can be easily swapped out at any time or the sheets shared with the players.

If you want, you can also leave space to either write directly with dry erase/white board markers on the plastic or affix laminated paper to the inside for scribbling notes too.

You can find my D&D 5e notes here: https://www.dropbox.com/s/fioeh1992pwzqq2/A5%20Screen%20Printouts%20%28Layout%201%29.pdf?dl=0
Simply print them double paged onto A4 and cut them in half.

Once this is finished, you are basically done!

Step 5: Additional Tips and Ideas

Decorate - This is your GM/DM screen, so decorate it as you wish! Use larger or the same size pockets affixed on the outside as to keep your designs interchangeable.

Initiative Tracking - Another idea for use of the notches in the corrugated plastic is to hold small cards on toothpicks to help you and your players keep track of initiative order.