How do you pour liquid from mason jars without spilling?

Trying to use mason jars to store my breast milk, but struggling to pour it without spilling. I tried stainless steel lids from Amazon but they leak. Found some plastic lids but am not sure if they’re safe to repeatedly sterilize. I’ve tried searching this sub but only see recommendations on freezing, so any tips on pourable plastic free (or sterilizer safe plastic) is appreciated.