Protagonist wakes up in unfamiliar world: good or bad?

I'm not sure whether it's a common trope - I haven't come across it that much. But if you're worried it about your own work, just approach it like any other trope. Use it only if you absolutely have to. Is this where your story begins? Is waking up in an unfamiliar world a pivotal plot point?

There will always be exceptions to the rule - like the oft criticised character-describing-themselves-while-looking-in-a-mirror device. If your story is about mirrors in a mirror world and your character is totally obsessed about mirrors, then it would be entirely logical for the character to describe themselves via their reflection.

Hey, that example's older than that - how about The Sleeper Awakes by HG Wells (1899)? I'm sure if I could be so bothered I could dig out a Classical story a similar start. It's a fairly popular way to go, partly because it's something we can all imagine (who hasn't experienced those moments where we've woken up rapidly and have been a bit confused about everything until our brain gets in-gear?)

One thing I've learnt from my own WIP is that having features that have been used before doesn't matter so much, it's what you do with it after which does. That and give me a plot setting / point and enough time, I could find at least three example where it's been done before.

Take the Harry Potter series as an example. There's the classic prophecy - in poor hands can seem really contrived. But it's taken in a new direction by the fact that the Big Bad heard the prophecy, and attacks Harry to stop the prophecy coming true - but in doing so, he makes the prophecy come true.

One place I've found invaluable is the site TV Tropes; excellent in listing various plot points / settings and what other media have trodden the path before you.

As a general statement, the more common a particular trope is, the more distinctive you have to make your version in order to get away with it.

For instance, one of the most overused tropes in SF and horror movies is where the group is stuck in a limited space with something, and they are trying to escape and/or kill it while avoiding being killed off one by one. Think Alien, Deep Star Six, Leviathan, etc etc etc.

There's no reason not to do another movie along this line, but you'd better do a damned good job of it. Or at least put a unique twist on it.

On the other hand, if you have a truly unique, novel (ba-Boom-tsh) idea, you can play it pretty straight and be successful.

It's a trope, and like all tropes, it can be put to good use, provided it's executed well.

In fact, some people enjoy some tropes and may even look for them. As a romance reader, there are tropes I enjoy, like Friends to Lovers and Surprise Baby, etc.

Anyway, nothing is truly original. You just need to put a fresh spin on certain overused tropes, but good writing is still important.

Like I said, look up TVTropes, especially of stuff you enjoy. You're bound to find out that many stories use (or subvert or lampshade) similar tropes.

http://tvtropes.org/pmwiki/pmwiki.php/Main/GoodMorningCrono