I am getting a new kitten soon, and I am hoping to socialize him like you have with Blackjack. Do you have any suggested reading as to what to do and when? I've managed to teach my older cat some of this, but I want to really do everything possible for this new kitten.
If you get the kitten as young as possible, you'll have better luck getting it used to new situations and various places.
Safety comes first: Buy (or make) a harness that fits the kitten. I did a tutorial on this a few months ago while making Blackjack's harness. Always keep the cat on a leash, even when it's riding on your shoulder or inside your sweatshirt. This will prevent the kitten from darting off if it's scared or startled.
The first step is taking the cat outside with you on short walks. Tuck it into a sweatshirt or jacket so that it's cuddled up close to you and feels safe. It may or may not want to poke its head out see its surroundings. Let it do as it pleases in this regard.
Being outdoors, inside a sweatshirt, gives the kitten a sense of security while still exposing it to new sights and sounds. Growing accustomed to these things will make the difference between a well-socialized cat and a scaredy-cat. The more that it gets used to, the better.
I can, for example, trust Blackjack to hang out at open-air markets downtown while I sell my wares. There's loud music, thousands of people around, dogs, cars, planes, buses, and all manner of crazy stimuli that would make a normal cat duck for the nearest enclosed space with a bottlebrush tail. Blackjack prefers to steal my lawn chair and watch the world go by with a nonchalant air of ease from his lofty perch.
Once the kitten is used to being around new noises and smells, you can start carrying him around outside the sweatshirt. If he sits on your shoulder, that's awesome. Blackjack preferred it when I wore a backpack so that he could ride on the backpack like so:
He was never really too great at walking on the leash like a dog early on, so he was certainly a rider. He likes standing on my elbow like it's a perch, but backpacks are still his favorite means of joining me for excursions around town. He feels safe up there, and his comfort is more important than the fancy of walking a cat like a dog.
Which brings me to my next point: People will look at you like you're crazy. They'll try to pet your cat. Your cat may not want to be petted, and, unlike a dog who may growl in warning, a cat might just upright scratch someone. Do not let this happen. If someone approaches the cat and wants to pet it, tell them to hold off and let the cat go to them. Do not force your cat to receive unwanted attention.
There's also the subject of dogs. Blackjack LOVES dogs, and wants to meet every dog we see on our walks. But not all dogs want to meet him on the same friendly terms. Unless you have dogs at home that you can socialize your cat with from an early age, it's probably best to avoid dogs altogether on your outings. Blackjack was raised with three dogs, and made friends with my housemate's friend's dogs while we were still living in the Attic. He was also bros with a pitbull for a while when I was meeting my potential new housemates before I got the condo instead. In other words, I know that Blackjack is a dog-savvy cat, so I don't mind him meeting new dogs on our walks. Even so, I always ask the dog owners if their pup is okay with kitties before I allow any interaction to take place.
Be diligent. Take your kitten out with you at least once a day so that it becomes normal for him to experience the outside world at your side.
Be patient. Not all cats have what it takes to be a shoulder cat. Some are just shy by nature and will not enjoy being outside one tiny bit. Blackjack yowled like a banshee the first time he rode in a car, but he quickly got used it and now rather enjoys car rides.
Don't force the cat to do anything it doesn't want to. It's true that not all cats can be shoulder cats. I was lucky with Blackjack due to the young age I got him at, and his breed; he's a Manx, and Manx cats are often called the "dogs of the cat world" because they are outgoing and tough as nails. I was able to condition him to be fearless from the age of about 6 weeks onward. My sister, on the other hand, has an adult tortoiseshell kitty named Mew who will duck for cover if she so much as hears a pin drop from across the room because she was raised in an abusive home before my sister adopted her. It's both a matter of how the kitty is raised and what it's personality type is.
Use lots of treats. If the kitty is scared by something, hold it close and give it lots of pets and lovings. Re-enforce the idea that everything is okay by giving it treats once it's settled down.
Anyhow, I've written a practical novel at this point, so I hope this helps! If there's anything I didn't cover, send me an ask and I'll be happy to give some more suggestions!