I don't do it regularly, just when I start looking like a monkey, but here's what I do. If I just want to do it quickly I use the trimmer, maybe with a longer setting, because it pinches. Otherwise I use a regular razor, like the Gillette ones and a bit of patience, it's surprisingly easy not to cut yourself. Sometimes I use depilatory cream, but be careful, if you put too much or leave it on too long it will burn for a few days.

Shaving Creme might work, since there are no blades involved

Try to get one that is not to agressive for your skin, maybe on specifically for more intimate parts

I have a waterproof shaver specifically for my balls. It is pretty easy to shave with it in the shower, just use one hand to stretch your sack out then run the shaver over it. It is the wrinkles that are such a danger.

https://www.softsheen-carson.com/magic-grooming/shaving-powder

So rumor is that for some people it burns like the fires of hell, but I've never had such problems so YMMV.

I've had to do it twice in my life, and I cut the hair with scissors first then used a cheap razor much like these: https://www.voordeeldrogisterij.nl/premium-laser-twin-wegwerpscheermes-10-stuks.html?id=272026839 Came off painlessly.

Double edge safety razor. Edwin Jagger DE8x is a good choice as not aggressive (the x doesn't matter, it's the design of the handle). For the blades, I use feathers, but it doesn't really matter.

No need to press. Just glide softly on the stretched soaped surface, in no specific direction, while lifting your dick with the other wrist and holding the balls with the other hand. For the shaft, don't go against the grain. You'll nick yourself (no big deal).

Also I typically reserve the brand new blades for my face, maybe it helps.

Dip it in conc. H~2~SO~4~

I use a Gillette Mach 3 and always shave toward the tip, no matter whether you are above, below, beside the shaft, below the balls, on the balls etc. I find doing it in a hot shower is sufficient and gel/cream isn't necessary with this method, though I have some Gillette Hydro gel I like. I just find it too time-consuming to bother.

Nair