Consistency is important, as others said, but in the end, I really don't mind. Just make stuff up. Your lasers are powered by dilithium crystals. Fine. Antigravity functions by protozoid negation radiation. Yes, please! Just stay consistent.

However, if you do explain something, be vague enough that it fits, like the omnigel entry up there. It doesn't say HOW it does it (well, not really), just THAT it does what it does. So we know what it does, have some idea why it has these effects, and that's good.
Or: if you explain something, even with pseudoscience, go all the way. Because if ypu explain it, people will follow you, nod their head (and probably suspend their disbelief a little) and go "ah, yes, I can see that". But if your explanation just stops after some "science, science, sciences, SPACE MAGIC!" the gap in the explanation just becomes more visible, and since you attempted to explain everything, people will be less likely to let it slide when you don't.

So either explain stuff very vague, or go all the way.