There used to be a coffee shop opposite my office that had a pull handle on the push side of the double doors. The right hand side doors were also often locked. I once sat at the nearest table to the doors and watched a dozen people pull then push on the right door, then pull and finally push on the left door, and often end up visibly aggravated by the time they got in and joined the morning queue!

The next day my debugging instinct kicked in, I bought some PUSH stickers and did some covert guerrilla ergonomic stickering. Problem solved and it made me smile every time I went past that cafe!