This is literally every conversation I have with investors, so here's my $.02.
Others have described great examples, so I will cover a different aspect:
I have found the use of (everyday) examples makes things more difficult, so I tend to avoid it like the plague.
The reason is that, for a non-math person, once we describe a single application their mind will latch on to that and never let go, especially if they are an authority in something else (e.g. business). If you describe a TSP, then this is suddenly all that OR is about, and that's it.
I have consistently found it excruciatingly difficult to overwrite that idea once it has taken hold. This is very nasty because it can happen in 5 seconds and can consume an entire meeting.
My strategy is to (i) refuse to name applications, or (ii) name at least 20 in a rapid sequence to make the point that the same technology is used for all of these things. In the latter case, I will specifically refuse to go back to any of those 20 examples and describe that in more detail, because I will politely tell my fellow human "that is not what this conversation is about. We can discuss that in another meeting if you want".
Non-math people are often smarter than us, so it's unfair to assume they have to be spoon fed. As long as we don't overwhelm them with jargon, they can keep up just fine, it just takes more skill to bridge the gap seamlessly.
The way I typically do it is to force people to think, so I say things like: "optimisation is a decision-making science. The results of optimisation tell us exactly how to run complex systems. Think about that for a minute".
I then build the conversation based on how they respond. This works because it's suddenly about them, not me.
Once we make a statement, people's mind will seek out the closest thing they know, e.g., "oh so is this like machine learning?". "No".
This can go on for quite a while, and we have to stick to our guns so that people become open to the idea that we are describing a truly new concept, so they can't be "lazy" and reuse their existing knowledge.
It is only after they are able to describe said concept in their own words that I feel safe describing any examples in detail.