My skin gets irritated when I shave. It gets irritated when I don't shave. I've tried electric razors and I've tried cartridge razors; the past few years, I've been using a Merkur 25C safety razor with Bic double-edged blades (which I settled on after a comparison of double-edged razor blades).
A couple of weeks ago, I developed a shaving rash, on the left side of my face, around and under my chin. I've been trying to get it to clear up, but haven't had much luck yet. (I'll try not to use the word "rash" again for the remainder of this post.)
I found some articles with titles like How to Get Rid of Razor Burn Fast, Simple Ways to Prevent Skin Irritation After Shaving, and How to Prevent Shaving Rash (hey, that one's not my fault; it's the title of the page). I also found my way to /r/wicked_edge, Reddit's Home for Traditional Wetshaving. It's...quite the rabbit-hole.
The users of Wicked Edge have some opinions on things. First of all, they don't much care for William's Mug, the cheap shaving soap I've been using, though several of them say that, if you add enough water to it, it foams up more and isn't so bad.
I tried that. I grew out my beard for a few days and then, when I couldn't take the itching anymore and it looked like the redness was clearing up, I shaved again. True to the Wicked Edge users' recommendation, more water meant better foam. But after a couple days, my chin started to flare up again. So I'm going to have to try something else.
And oh! there are so very many things to try. Blades! Soaps! Oils! Moisturize more! Moisturize less! Use alum! Use witch hazel! Stop using astringents! Lotion-based aftershave, alcohol-based aftershave, stop using aftershave! Ultimately, the challenge is that everybody's different, and what works for one guy won't work for every guy.
For now, I'm growing the beard back out, hitting the irritated skin with tea tree oil (a couple of drops on a wet cotton pad) and aloe vera (straight from the plant) a couple of times a day and hoping it'll go away soon. Once that happens, I've got some new stuff to try.
I saw several recommendations for Voskhod razors as providing a smooth shave without being too sharp; I'm going to try those. I know my technique needs work; I'm in a habit of pressing, which I need to unlearn because I know that's contributing to the irritation.
I also saw a number of soap recommendations. Consensus seems to be that the best soaps are tallow-based, but I'm not big on animal products; fortunately, there are lots of recommendations for vegan soaps, too. I ordered a few samples from Maggard Razors; I'll try them out, see if any of them work, and plan on reporting back later.