Write expiration date on purchase immediately
I'm so tired of always looking for the sometimes very well-hidden expiration date.
I have started to put my glasses and possibly a magnifying glass after each purchase, then everything that I keep longer, immediately labeled large and clear with the expiration date.
For pharmaceuticals, I also label the blister packs, with tear-off tablets, every single tablet.
I save money because I do not throw away so much because I'm unsure. Maybe this tip will help you too!