Revealing just enough

One of my favorite parts of revision is balancing what I want to spell out explicitly with what I want the reader to figure out. How big are the bread crumbs I should leave, and how far apart can they be, for the reader to still be able to follow the trail?

Some things I only want to suggest, to hint at, to foreshadow. Some things I want the reader to have the thrill of discovering--or even of deciding. Yet I can't be too vague.

I'm doing such a revision now, deleting repetitions, trimming where I've over-explained, cutting back to make room for the reader. I'm also adding a few words where I realize I haven't been clear, have assumed too much. Seeking, the whole time, a perfect balance.