ULPT: Flights to Tel Aviv are really-really cheap right now, and with a layover in Frankfurt, or London, or Paris you can -winks- "miss your flight" and get a cheap flight to a nice European city that would normally cost 5x as much...

A few sites already do searches for this specifically. The first one I can think of is Skiplagged, but there was another one (I think eDream or something like that). There's nothing wrong or illegal about it. Airlines have threatened to ban passengers over it, but I've never heard of it actually happening, and I know people that have done it a lot. It can be a little trickier on international flights because some countries require a full itinerary for passengers who plan to stay instead of just transit. Changing your plan may lead them to question you at the border, but they are likely to not care once you explain the situation. This won't be an issue for the Schengen zone as they don't really care. So, that flight is fine. Make sure you don't book a round trip ticket as they will cancel your return trip if you don't finish the outgoing trip. Also luggage can be tricky. Some people ask the airline to check their bags to the place they plan to stay, and it works, but I wouldn't check anything. Sometimes airlines will compel you to gate check rollerbags which can be a problem. Just make sure you tell the gate agent to check it to the first destination if that happens. Just say you need something out of it during the layover. So yeah, just only book one ways and don't check bags, and you are good to go for the most part. This is really good when the destinations subsidize flights going there. Places like Las Vegas and Orlando are known for that. They subsidize the flights so people who are shopping for a vacation will choose it to "save money" when in reality they are going to waste a lot more there than they would at the beach in Aruba.