Thanks for sharing that process, Buka. I am working to use sparring more than I experienced, and this gives me some food for thought as I develop my own process for starting them.Sparring isn't about winning or losing, it's about sparring, it's a process that eventually led to learning how to fight. We all won or lost every day we sparred. We did different forms of sparring, Karate style, boxing, kickboxing, a variation on point sparring, a mix and match sort, and eventually (nineties) grappling.
The first time any of my students sparred it would be with me. Usually after a class, off to the side. I'd talk them though it, explaining rules, target areas, control, how everyone would go just as hard as they did - and subsequently how they could go as hard as their opponent did. I'd gear up, because I hate sparring with white belts. I'd usually spend a half hour with them, maybe more, maybe less, depending on their natural inclination for it.
I'd explain why they have to keep their hands up at all times and lightly show them that getting hit in the face would not kill them. I believe getting hit in the face is the biggest fear a new student has, closely followed by being embarrassed in front of others. I also found it quite common that a lot of students were just as uncomfortable hitting another person in the face as they were getting hit. I believe I understand that, believe it's a good thing, and believe it's easy to deal with and overcome.
I'd explain openings, blocking, countering, distance, jamming, evading, footwork etc. Sounds like a lot when you write it down, but it's pretty easy when you're moving around with them. They won't understand all the concepts at first, I just want them to be aware they exist. I'd explain why a cup and mouthpiece were the first thing they were required to have after a gi. (Everyone in my classes wore a cup in class every single day). Groin was an acceptable target area with us.(not in boxing, obviously) (And, yes, there were occasional cup checks, usually a snap kick)
I liked to get a feel for how students moved and hit when they were new. Some young guys were "fear biters", like with dogs (not trying to be insulting) who bit people out of fear more than aggression. These guys were scared of sparring, usually pretending they weren't, and tended to strike way too hard coming out of the gate. The only way for me to have a good handle on that was by teaching them sparring myself. It made it easier to match them up with other students later on during an actual sparring class. I wouldn't match them up with another white belt who I felt was somewhat shy. It was usually pretty easy to teach good control. If not, which was rare, you just fed them to the dogs. (Green belts. All green belts were fricken' nuts. It was an actual requirement. Seriously)
The reason I spent so much time with each student, especially kids, was I felt that sparring was an integral part of the Martial process. (just my opinion) and we were a contact fighting school. In that type of gym people can be intimidated or frightened away altogether if not taught properly. Also, before anyone could join they had to watch at least two classes, one of which had to be a sparring class. And with kids, at least one of their folks had to watch the kids sparring class. I'd get parents who said, "I don't think my child could do that." I'd tell them to come back again when I taught a new child how to spar for the first time. They usually signed them up right then and there.
Anyway, that's how I did it.