Continuing my writing theme of beginnings …
There's a lot of writing advice out there on ways you should never begin your story. And it's mostly right. There are exceptions, but you should think carefully before deciding that you're the exception.
Never start your story with:
1) The protagonist (or any other character) waking up in the morning.
It does seem like a logical place to begin and a good way to show the ordinary world before the character's life changes, but do we really want to read about someone waking up, having breakfast, getting dressed, and otherwise starting their day? I suspect that another reason this is popular is that it does show up frequently in movies, especially romantic comedies, where the heroine starting her day is the sequence that goes with the opening credits, while the movie's theme song plays. It's a good way to establish a lot of the character's traits and establish the story world. But in a film, the more visual information you can cram into that sequence, the better -- show whether she's a neat freak or a slob, how does she dress, what does she wear, what's her attitude, what's her routine, etc. -- while in a book, all that kind of detail just bogs down the opening. It's better to start as close as possible to the point where the character's life changes. Skip the teeth brushing and dressing part.
EXCEPT this can be a really shocking opening if the character wakes to something she doesn't expect to find, like discovering herself in a strange place or not knowing who she is. But then you're not going to get that going through a normal routine stuff because there is no normal. Or if you plan to make things seriously not normal within a few paragraphs, then it works to start with a very mundane beginning. We meet Arthur Dent in The Hitchhiker's Guide to the Galaxy when he wakes in the morning and goes about his morning routine, with the tiny detail of seeing a bulldozer outside his house slipped into the mention of him opening the window, and then it takes a little longer, until after he's made coffee, before that thought catches up with him and he runs outside to confront the bulldozer. But you need to establish within a couple of paragraphs that something is really crazy.
2) The protagonist traveling somewhere and thinking about where she's going and why.
This is a very popular opening for romance novels, even some that get published, but it's become such a cliche. Unless something happens during the journey, the story either starts when she makes the decision to go, and then we can skip to the part where she arrives, or it starts when she arrives at her destination. The character sitting in the coach/car/airplane/train and thinking about her entire backstory makes for a dull opening.
EXCEPT you can play with that trope and make something happen. I got a book out of that when I was snarking about the trope and then wrote a book that opens with the heroine on the train thinking about the new life that faces her when suddenly a group of bandits robs the train, and this is what actually changes her life (though she doesn't know it at the time). The thing to keep in mind is that you need action, not thinking.
3) An exciting action sequence that turns out to be a dream.
This is a double whammy because first there's the letdown that that the exciting thing didn't actually happen, and then you get that "waking up in the morning" opening. This kind of opening can make the reader feel betrayed, and it looks suspiciously like an attempt to provide something exciting for the opening because you didn't have confidence in your real beginning. It also means that you've wasted pages on something that actually has no consequences.
EXCEPT I think this can be used judiciously in fantasy if it's a key element of the story that the character has dreams that are either prophetic or that provide a view into other people's lives. But you'd need to show us pretty quickly that this is what is going on. Like within a paragraph or so of waking, something in real life needs to happen that echoes something in the dream. You would have to use the dream to create a sense of danger and unease, not do the "whew, it was just a dream" kind of opening.