I think I've mentioned somewhere else that when you play a song you like to someone else you hear it through their ears. It's something to do with mirror neurons firing.
It's a useful trick for practicing presentations, knowing that work is really both right and good and generally avoiding any pitfalls.
It's one thing to rehearse a presentation in your head, it's quite another to do it to someone who has nothing to do with your project. Suddenly you can hear yourself from their point of view, you know which points are too long,too short, too fuzzy and simply not well though out.
Same goes for creative work. I watched someone in my team present some work that's been months in development. Being on the receiving end of someone explaining everything, sitting with clients really made me objective by seeing it all from a totally different point of view. Thankfully it stood up, and we even saw ways of making it better that hadn't been clear before.
So talk to someone, not just when you're stuck, when you are totally sure. There's nothing like having to explain yourself to see where you can make things better,