As a gentleman (and I believe also a lady, although we are not supposed to mention this!) advances in years, one of the pleasures in store is nostril hair. And then ear hair, but that is a whole other story.
Naturally, the done thing is to trim it so as not to cause offence to your fellow man.
However, what I do, and I suggest you follow my example, is to keep one really long nose hair. You can fold it in half and tuck it away. If you are in a situation where you might find yourself nodding off (e.g. boring meeting at work, lecture, classroom, etc) then you can, discreetly of course, give it a sharp tug. Mildly painful though it may be, I find that this has the useful side effect of jarring you back into full wakefulness.
Let me know how you get on.