I have tried a few ways and my way absolutely works best for me. I pick out a bright star at night.Point my binoculars at the star,cover the front of one eyepiece with one hand,leave both eyes open,slowly move my hand out of the way.
If they are not colliminated, I start to see a weird mishapen ghost image somewhere in my field of view, in addition to the star. As I move my hand away more, at some point my brain realizes that the forming image is looking more and more like the star.Then my brain tries to align the two images. Untill that point I can see where the two images are in relation to each other and therefore make corrections.
Test, correct, test, correct.It works for me.