mix non-iodine sea salt with as hot a temperature of water as you can stand and soak your nose in it. i usually put it in a coffee mug (least awkward container to have your nose in for a while lol). I do about 1/3-1/2 a teaspoon of sea salt for a coffee mug of water. Try to do it for up to 5 minutes (I get lazy sometimes because the position is so awkward) and around 3 times a day. This will prevent the notorious "nose bump" people get with nose piercings, as well as heal a nose bump that started. It usually takes a few days to get rid of one of these bumps. I have two 18g nose piercings on one nostril (one stud and one hoop) and sea salt rinses are the only way I ever use to clean them. Also, try to avoid having your jewelry out for a long period of time, and don't change jewelry a lot. Even nose piercings that are years old will want to close after a few hours of no jewelry in, and will make it uncomfortable and irritated to try to get jewelry in.
You may use sea salt to clean your piercing. You may use sea salt solution twice a day or at least once in the night before you go to sleep. Remember – not to use ordinary soap to clean your piercing, they are just too harsh- so be aware of soaps.