When I think of foreshadowing I think of something simple happening in an early chapter and then later that simple thing becomes something more. However, according to one of my "help" book foreshadowing can occur from sentence to sentence. This has opened a whole new awareness for me. After reading that passage in my "help" book I realized that I use foreshadowing more than I thought I did.
Of course foreshadowing is also done chapters apart. I have a flower that plays a part in my novel. My protagonist has two romantic interests. They both give her flowers at different spots in the book, but they both give her different flowers. I make a quick mention of what flower she likes in the beginning without really coming out and saying that she likes it. It's just a quick mention, but when she receives the one she likes the reader will know it instantly. Before she even says that it's her favorite flower.
I also like the idea of foreshadowing in one book and then having it pay off in a later book. Since the book I am working on currently is intended to be the first in a series I hope to make use of this type of foreshadowing.
I am still working on this aspect. I don't want to use too many or not enough, so I tend to work on my foreshadowing during revisions. Hopefully, I will strike the perfect balance for my story by the time it's completed.
Till next time enjoy your day!