This is neither new nor in any way special, but I wanted to make my own for simplifying doing my laundry: The T-Shirt-Fold-O-Mat.
Just grab some large enough cardboard, cut the pieces to size as shown in the drawing below and tape it together. I used cheap package tape because it was lying around – works perfectly. Here’s the plan:
Using it is a piece of cake and it speeds up stowing away my shirts properly (I just like that).