The classical Movie Introduction Sometimes, you get a hero. Not over time, but right at the start this is your hero. He's confident, he's suave, and he always packs his shaving cream. Somehow he always manages to get that beard just right, despite the fact that you've never seen him trim. Everything about him is admirable, and you just wanna follow him like a little puppy dog because that's how AWESOME he is.
it might work, but you still shouldn't do it. It's one thing for movies, where you can simply follow someone's action across the screens. In books, you want the closeness that only seeing the character fall on their face time times just to get it right once will bring.
The stumbling introduction - sometimes, your character stumbles into the wrong thing at the wrong time. Or the right thing at the right time, perhaps, but if you want a good story you should probably make sure it ends up worse for them than it would have otherwise.
Oh, sure, things can END alright, but I think most of us find it honestly more fun when we see the helpless character stumbling about; plus, your audience will like them more for being introduced.
The Angsty Opening Introduction oh, god, these are horrid and I've DONE one
You shouldn't start out with a character reminiscing about how horrid their past is. It doesn't set the mood; it makes them prepared for the worst. If you insist on doing it anyway, you better make the story so good that you meet and exceed the expectations already set in place assuming you didn't just make it so angsty that they assumed it would be horrid to begin with and stopped reading right then and there.
The voiceover opening introduction it's like the angsty one, but without the angst. It might be from the character, or it might be from someone else. It sets the scene but lets the story tell itself without coloring people's expectations. It's a good way to go if you want to introduce someone into a setting that might not make much sense otherwise.
The Destined Introduction this generally goes with the stumbling introduction, but it's where some destiny is introduced early on. When you do this, you're pretty much letting everyone know "Yeah. That idiot's the chosen one." That isn't a bad way to go, either, but keep in mind if you're going to do the destiny one that you can take it too far quite easily. Keep the power levels down, make everyone doubt them make them doubt themselves, for that matter. Or make only them be the doubters, running away from the destiny that they were supposedly born from and which everyone has expected them to accomplish from birth. Maybe they never even got training, because there was some vague sense of "You're going to save us one day," and not much else, or they only got training and they're finally rebelling against it. Maybe someone doesn't want them to save everyone, and they've been chased from their homes by opposing forces and they don't know how to deal with it because
well, dang it, "I'm supposed to be the chosen one!"
It can also be surprisingly fun to deprive these people of their status.
Or to make it work out completely differently - like "Saving everyone," by turning into a girl and continuing the female okay, that might be a bit too cruel, but a chosen weapon of girlification can be fun, particularly if you want to bring some gender equality into the story WITHOUT relying too heavily on a feminine side you might not be in touch with yet. You should still have side characters that are female, mind you, if only for the main character's sanity but some people might find this an easier option than throwing their entire weights behind a gender they don't know. (The same goes for girls writing with guys, but that might send a different sort of message unless you're willing to rewrite that world as being ultra-feminist and against all males.)
The Forced Introduction sometimes, someone else introduces the main character. Maybe it's summoning an assistant, laying a spell, or bashing them over the head and kidnapping them for marriage, but somehow or another they are DRAGGED into the story. They don't want to be there, but they're there, and they've been introduced quite nicely. This is a wonderful case for those of you who want to give the damsel her own back and let her do her own rescue.
The "horror," introduction something bad has happened. That's all that matters. The city has been destroyed, or the world is on the brink of destruction, and you have to go do something right now. I personally would like pairing this with the forced introduction maybe while your "damsel" is plotting her escape, her knight is trying his best to save her,. The two clash in their plan, everything spins into chaos, and oh, wait, I'm plotting out a Robert Jordan book. Let's face it, any basic plot is going to be in one of those things; take your pick, and RUN with it!
Accidental Introduction probably best for a side character, but this is the mini-version of a stumble. They run into the person, they walk out with the person, or else go on their own path because of what happened with the person and do something interesting that we all want to read about. Short and to the point, but still a bit interesting, so long as it doesn't look too contrived; introducing someone for the soul purpose of creating a secondary plotline is never a good idea, without at least giving them something to do in that moment of time.
The speaking introduction sometimes, you don't need to introduce someone. Drop them into the middle of an interesting conversation, and they'll learn the characters by watching them. They'll smile, they'll laugh
and then you'll probably rely on one of the former options to introduce the story itself, anyway. But it's still a good start.
Introducing my main character gave me trouble, earlier I decided to go with a forced/stumbling introduction, personally brought into another world by magic, but without any way of knowing who (if anyone) was responsible, so he stumbles through things. It annoyed me enough that I decided I'd write a guide to help anyone else having trouble, though I did do this earlier then I'd promised myself I would. *Sighs at my inability to weight*
Anyway, have fun, particularly if you're doing nanowrimo and don't just limit yourself to main characters with this, either!