Usually saying “Don’t forget your passport!” will not work or worse set you up for forgetting. What to do? Luckily I have a nice little procedure for you that works really, really well for me.
When I want to make sure I remember to do something, I mentally link it with an event that I am sure will happen. In our example that would be : “When picking up my bag to leave the house, I will think of my passport, and retrieve it”.
The trick here is to really picture the event, and your passport. The more vivid this picture or short film is, the more effective this procedure will be.
Linking stuff has long been a standard mnemonic trick to remember random items on list. And it works. Your brain is set up to walk along connections. So if you connect picking up my bag with thinking of your passport, your brain will bring up an image of your passport the moment you pick up your bag to leave the house.
Try this with small things, that don’t carry a lot of emotional relevance first, since you will be much more open to experimenting and finding your personal way to implement this much easier when not stressed and result-agnostic.