Glad you asked, this step is crucial! You’ll probably find your hair grows in different directions in different places, so take note. You’ll want to shave “with the grain” in each area. Watch out, the neck can be tricky! You'll likely the notice the hairs grow in at least a few different directions there.
Here is one quick way to find the grain. Start off but looking closely in the mirror to see in what direction your hairs point. Each area may be different. Also, pay attention to the angle, your hair likely doesn't point straight up or down everywhere, it may grow diagonally.
Glide the long edge of a credit card along your skin to see in which direction your are pulling the hair up, and which one you are laying it down. The direction in which you are lifting the hairs is against the grain, and the direction in which you are laying it down is with the grain. We strongly encourage only shaving with the grain.