I think the most important thing is internal consistency. Readers can accept quite a lot of weird, cool sci-fi stuff as long as it isn't complete nonsense, and your story takes its existence into account properly.  People are fine with there being cheap forcefield generators you can buy from convenience stores that are the size of small coins, but will become annoyed if people inexplicably aren't using them when gunfights occur.
They may also be a little doubtful if later there is a, say, building scale forcefield that requires an entire powerplant to keep online, despite the personal ones being able to stay charged with only body movement.

Basically, just think through what impacts a given "magical technology" would have and make sure your world reflects that, at least on some level. You don't have to be insanely thorough, but you should try to patch any glaring issues where the technology would definitely and obviously solve a problem, but that problem is still around for some unexplained reason, and features in your story.