Dr. Mike Benninger, an ear, nose and throat doctor at the Cleveland Clinic, says especially when it is cold and dry outside, you should try to blow your nose when it's moist. So even if you think it's gross, it's actually better to blow your nose while you are in the shower.
Throughout the day, if your nose is dry, you can use lotion. Just make sure it is not scented and it doesn't have any alcohol.
As for blowing your nose really hard, it won't cause damage but Dr. Benninger says there is a small chance it will propel some mucus back into your sinuses, where an infection could start.
Another great way to clear out the passageways is by using an irrigation system such as a Neti Pot or steam from a humidifier. Many of my friends swear by the Neti Pot! But here's a word of caution: If you use a Neti Pot, you should be using either the saline solution that comes with it or distilled water (not tap.)
Happy nose blowing everyone! Here's to clear sinuses!