My squat is progressing, and couple of days ago I reached 70 kg. It's not much, but it is a nice psychological step, my bodyweight. I've been very disciplined in training so far. In retrospect I understand that the main cause of injury is progressing too fast and not backing off. It's good to talk about intuitive training, but not everyone is good at it. In fact, it's probably the minority of very experienced loifters who have good feeling of their bodies. For me,when things go well and I make new PR, the desire is to do better and better. Which I do and... get injured.
I am following ladders described by Shaf. One rep, short rest, two - rest, three - end of set. It manages the fatigue well and does not let the muscles of the lower back to get too tired. The goal is to make every rep crisp.
There are two ways to cycle the load: reduce it or skip the workout. So, training heavy, medium, light three times a week or heavy once a week is similar in a way, except for the weekly volume. I try squat once a week and do other exercises on other days, mostly military barbell press or weighted chinups. The main focus is on squat.