Nasal Pillows---how do you use them?

I got a nasal pillow mask last year; I used the smallest end, and didn't remember what to do with it. It wouldn't stay just barely inside my nostrils, and wouldn't go any further in. I've mastered several masks, all nasal or full face, but after a year, I can't remember how it's supposed to go in. I know there are several fans of nasal pillows, so someone must have some ideas for me.

Try a larger pillow size. The outside rim of the pillow should rest outside of your nostrils, not inside.

I agree with greyhound.
Even though I have a smallish nose, I discovered that the large pillow size was best for me.