When do you cut away from the action and fade to black? What sorts of action do you put off-screen, or cover in a short recollection?
Deciding what to show and what not to show is a difficult and important choice. So important, and so difficult, that many book-to-movie adaptations fail because of it. The Lord of the Rings is an interesting book to bring up in this context, as most of the battles occurred off-screen in the book (or were simply very short) and the slow, personal dialogue and character building occurred completely on screen. Likely there wasn't a meal in the LOTR that wasn't fully covered (sorry, I'm not going back to check) but the battles, when they were on screen, were often short, with details glossed over.
Deciding what kind of action you want to maintain is something you should think about. Does all your romance happen off-stage? All your battles? How about meals? You should have at least one instance of these on-stage, but the rest of these incidences are yours to deal with as you see fit. You're going to have to put something off-stage eventually -- not every second of your character's life is exciting (which is why we rarely if ever see protagonists' poop) -- so you need you decide: What is the focus of your book?
Books aren't movies, and often adaptions of books to the screen infuriate people, and there's myriad reasons why that is, but there's one in particular that has to do with what action happens on-stage (or screen, by this point). And that is the sheer fact that there are going to be less scenes in a movie then there are in a book. You can read a 1000 page novel over the course of weeks or months (or a weekend in my case) but the movie for such a thing, including every page and scene, would be insufferably long. Even if you released like ten movies, no one would likely sit through them. When a book gets adapted for the screen, the director has to sit down and decide what scenes are the most important. It's the same thing you do when you're editing your book, or getting it edited. Scenes will disappear, change order, or even appear brand new because a void you didn't notice before has now become apparent.
Making a movie just requires less scenes. You have to pare down further, condense, merge. Nuances have to be removed or modified otherwise you might spend 45 of your 90 minutes of movietime explaining why your MC feels a certain way about strawberries because of that thing that happened.
When you're deciding on what scenes to put off-stage, think of the movie your book would make. Ask yourself if one of four things would happen if you took a certain scene off-stage.
1. Nothing - this is the worst one because it says your scene isn't necessary. If the message and plot and character development all stay on course and strong with this scene missing, cut it. Move it off-stage. It's not necessary.
2. You'd miss it - This is close to nothing - you'd miss it because you like it and it has some stuff that you think is pretty important or cool or interesting, but when removed the plot is mostly unchanged and the characters are still 98% recognizable. In this case, try cutting it completely, but see if you can fit that thing you liked from the scene in somewhere else. When writing a book, your brain has a way of building a puzzle with missing pieces that you later put in with stuff you already made. Picking something up and putting it somewhere else can sometimes improve your novel.
3. It's worse - Great! That's what we want. Scenes that are essential and moving and powerful. Without them, the book is nothing. If everything's worse with this scene gone - keep it!
4. It's better - Also great. If you remove something and it turns out that your book flows better without that scene in there, don't take it as a disappointment. The following scenes would never have happened the same way without this one that you're about to cut, and that means that even though your book is better off without this trashy scene you'll never want to look at again, it was absolutely worth writing.
This may have gone further into editing than staging, but I think they're intimately connected. Deciding what to show and when matters.
To sum: Decide the theme of your book, and what kind of scenes you want to focus on, and have make the most impact. It could be that your book is all dinners instead of all battles. Once you've decided what kind of scenes you want to show the most of, figure out which ones actually matter. Remember, we live in computer land now, so you don't actually have to delete anything anymore - you can just Copy and Paste it away into some folder of hell that you will never actually look again.
Good luck out there!