People with facial hair, how do you shave/trim?

[Dystopia]

A single blade razor would probably do a "good enough" job, but if you want a closer shave then you either need multi-bladed razors, or a straight edge razor (though with the straight edge you risk cutting yourself more).

As I've mentioned, safety razors contain two edges, each with one single blade, and they do a better job than any disposable and probably most cartridges as long as you have fresh blades and the proper technique - Multi blades does not equal a closer shaver, that is only true if the blades are high quality - Two high quality blades will do a better job than 4 low quality. A straight razor is a great shaving tool but it requires training and technique - Honestly, most people who get into the hobby watch lots of videos and even read books and when the time comes to shave for the first time with a Straight razor they'll be so careful with the technique and pressure that the nicks you get are not worst than the ones you get with a regular cartridge or dispoable razor.

I don't know if you use cream to maintain your beard, but I used a small amount of shaving gel to soften my skin - There isn't a large difference for me between two or three or four blades, the closeness is basically the same.

I mean, technically yes you can, but you really shouldn't. You increase the chances of razor burn and skin irritation because you are pulling the hairs in the "wrong" direction. Even when you've shaved with the grain first, you shouldn't do it. Oh, and you also risk causing ingrown hairs.

Just curious about something - We are always careful to teach young men to not shave against the hair's growth patterns but we seem to be ok with shaving body hair against the grain due to the need of getting smooth skin - Why does this happen?

Yes, many barbers recommend shaving just with the grain - My barber only shaves with the grain, if you ask for a close shave, he will ask permission to use a straight razor or a shavette (basically a straight razor with replaceable blades) because those provide a close shave with the grain. However, for people experienced who have the right skin you can successfully shave against the grain after shaving both with and across it and make sure you apply enough cream. I've successfully managed to get what wetshavers call baby butt smooth skin by shaving against the grain without any kind of irritation, but I used lots of cream, had a hot shower and shaved accross the grain first. I think shaving across the grain is useful (basically shave sideways to growing pattern, for example I shave from the ear in the direction of my lip/chin) because it doesn't irritate as much as provides a closer shave. Also, doing something like a 45 degree angle against the grain - Basically not fully against but slightly turn your razor against the hair grow - Can be useful

The reason for multiple baldes isn't to shave more hairs in less passes (though I'm sure it does), it's the shave closer to the skin. There is a good reason for wanting to shave more hairs in less passes as well though; namely, that the less passes you need to make, the less chance of getting razor burn you will have.

This is where I don't have scientific understanding - How does more blades get a closer shave? If I pass the same blade on the same skin area I will not get a closer shave as the hair is already cut by the first blade. Can you explain it to me better? I agree that shaving in less passes is useful, that's why I finish with my second pass and only do little passes on the first part of my shave. I still don't see how more blades gets a closer shave - I know Gillette says it, but Gillette is known for lawsuits against overpriced items and dishonest marketing that is unfounded