Of course, that last example works best if you can bring in her climbing history without slapping a big fat THIS IS GONNA BE IMPORTANT label on it. Maybe you show it in bits. She's excessively uncomfortable, to the point where it seems out of character, about visiting the rotating restaurant on top of a skyscraper. A "surprise" date where somebody takes her to a rock climbing gym does not go well. It doesn't take much; the object is to drop hints subtle enough that they won't appear as big red flags to the reader, but will give them an "Aha!" moment when the only way she can rescue herself and her friends is by going up that cliff.
Foreshadowing ploys change over time, and it's a good idea to be sufficiently familiar with current work in your genre to recognize what's being done - and overdone. In the seventies you could identify a Gothic romance by (1) the cover (blue tones, dark tower, girl in a negligee fleeing the dark tower) and (2) the near-certainty that at some point the heroine would say, "Had I but known...." Writers of Gothics may have destroyed HIBK as a foreshadowing device for all time.
What's inspired me to think about the virtues of subtlety and restraint in foreshadowing? I recently read a thriller by a writer who is infinitely more successful than I am, so how dare I criticize anything he's written? Well... this book starts with a tiger heist, the details of which are a lot of fun to read. Scenes with the bad guys throughout the book establish that they quickly kill one of their two tigers for body parts but keep the other one alive, presumably so its parts will still be "fresh" when they get around to it.
So... by the time this tiger has been kept alive and in captivity for 80% of the book, you KNOW it's going to eat somebody. And by the time it does get loose and chow down on a villain, you're not shocked. You're not surprised. You're more like, "So what took you so long?"
And I consider that a waste of a perfectly good tiger.