A thing I noticed had a dramatic effect on my sleeping was forcing myself to keepy my mouth closed while doing any sort of excersize, be it running or calisthenics. It forces my entire nasal cavity to empty all the mucus, and I can breath significantly better and my sleep improved dramatic.
I was having problems breathing through my nose too. It led to snoring and I felt like a had a blocked nose more often than not. Other than forcing myself to breathe through my nose I also got one of those sinus rinse bottles and did some salt rinses.
It's made such a huge difference. After years of having a blocked nose I sometimes just take a moment to enjoy the fact I can breathe through my nose at last. I've also gone from being a snorer to a "very quiet sleeper" according to my girlfriend.
