I've read some stories with absolutely awesome world-building. I've read some stories in which the world seemed to be ordinary contemporary Earth. Guess which of these is more likely to get selected for our issue?
I believe every work of fiction involves world-building. The key is to make your world internally consistent and believable. I've said before there are no rules of writing, but one could approach world-building in the following manner:
- Begin at the beginning. Ideally when you start your story (or at the beginning of your second draft) you know what your story is about. Pick the most important world-building element of the story and really develop it.
- Look at all the other elements of your story. Are they consistent with this nascent world? For example, look at language including curses, metaphors and similes.
- If you enjoy research, ask questions about your world. For example, the Science Fiction and Fantasy Writers of America has a handy list of questions here. These include pretty much anything and everything you can imagine.
- Once you've developed all this, don't info-dump.
Good luck with your world-building!