Most upvoted comment
How do you prevent this shit?(r/wicked_edge)
The one-word answer is “practice,” but more helpfully: Do you prep well: shave after showering, wash your beard at the sink with a good pre-shave soap, and take your time lathering, paying close attention to your neck. You want the stubble fully softened.
Then shave with a blade that’s good for you. (See this post for more blade information.) Focus on keeping the leading edge of the cap, just behind the blade’s cutting edge, in contact with the skin, but not pressing the skin hard enough to indent it: just touching the skin. Let the guard go where it will—just ignore it. (Some try to get a good blade angle by making sure the guard is always touching their skin and thus often get too steep a blade angle.) The guard will be there if it’s needed, so you don’t have to think about it.
For now shave only with the grain, rinse, relather, and shave across the grain. It’s important to know the direction of your beard’s grain, obviously; this interactive diagram will help.
After the final rinse, glide the alum block over your wet beard and let it sit while you clean up and put stuff away, then rinse, dry, and apply aftershave.
You can find much more detail in my introductory guide; the reader reviews will let you decide whether you think it would help you.