Study. First thing I would suggest is studying noses, look at lots and lots of noses, photos, real life, a mirror, wherever. Study and break down the nose into shapes you can easily understand. Use what ever shapes you’re most comfortable with, draw lots.
Explore Variety. Noses vary a lot, I tend to find everyone has their own ‘ideal’ looking nose they default to (like me, I pretty much only draw one kind of nose), but for practice you should draw all kinds and mess around. You can play with size, make things pointy, tilt them up or down, thin or bulbus etc. etc. Cartoons are a good source to see how you can exaggerate. A distinctive nose is a great way of locking down a character’s look.
Simplify. You may find that when you draw every line you see on the nose your drawings look ugly. Best way to fix that is to simplify them and drop out unnecessary lines. Now how far you go is entirely up to you and down to both personal preference and the style you may be going for. What I tend to do is just draw the nostrils, and then just shade underneath. But there are no real rules and loads of different ways of representing noses:
I dunno if any of that helped, best of luck anyways! ^w^;