If you want to get somewhere or achieve something, you need to focus. More specifically, you need to focus on whatever you think (thinking must be only a starting point, you should always measure) it’s important either for you or for your product at this very moment. You can safely ignore and neglect everything else; it will only sidetrack you and keep you from reaching your real goals (note that goals can and should change, just not too frequently).
Turn off all distractions (you know what your distractions are), forget about the outside world (if only for an hour), focus and to the hard work.
Yes, it really is as simple as that.