When you have a cold or a stuffy nose it's best to use a wedge cushion to lift your back and head up at an angle which allows your sinuses to drain properly.
You can also use some pillows to lift your back and head up at an angle which will help your sinuses drain and relieve the stuffy nose.
Also using a humidifier and taking a steamy hot shower can help relieve a stuffy nose and congestion as well as staying hydrated and taking some decongestant medications.