There are a myriad of ways to get rid of a stuffy nose. Some methods that tend to work better than others for different people. Once you find what works, you can implement it when you feel a stuffy or blocked nose coming on and take care of the problem early on. One remedy many use is running a vaporizer. You can put an additive in the water such as a vaporub. The air will become moist which will loosen the sinus blockage. Stuffy noses are usually from inflammation rather than actual mucus buildup but you can be sure to blow your nose out good before implementing this remedy.
Another solution is to run a diffuser with essential oil in it. Eucalyptus mixed with lavender is excellent to unclog a stuffy nose and to relax your entire body. If you are not laying down, you may want to substitute lemon essential oil for the lavender so you don't get too relaxed and fall asleep.
There are a number of over-the-counter medicines that will unclog a stuff nose. Sometimes they actually do the opposite though so do be careful. Look on the label to make sure you get one that is for your exact symptoms or you'll be in for double trouble.