I have learnt to race cars over the past 5 years. I can lap and lap and lap, but the greatest improvement comes from the breaks between sessions, which can be minutes, hours, days or weeks. I stumbled upon the most effective strategy the other week when training in my simulator: I was doing a small number of laps, say between 7 and 10 then returning to the pits. I'd reflect on how the "stint" felt for a couple of minutes and then have a look at the telemetry, comparing laps and correlating my memory of the on-track experience with the sensor outputs that I could see in the telemetry. After doing this for 20 minutes, decide on some small setup tweaks and jump back in for another 7-10 lap stint, rinse and repeat.
I spent maybe 3 hours doing it and drove maybe 50 laps during that time (I could have done over twice that number if I hadn't taken my approach), but the improvement I got from it by the end was far and above anything I've tried before.
I can also relate it to another time in a real car where I was learning a new track and car in a short 20 minute session. I had done ~15 minutes on track and the session was stopped. I got back to the pits and sat in the car. I asked my engineer about the time I'd done in relation to other drivers and just sat there in the car thinking through my laps and where I could be "better". I went back out on track for the final 5 minutes and made a huge improvement, finishing top. It wouldn't have happened without that brief period of reflection.
TL;DR Do what you're doing for the shortest meaningful period of time. Stop and reflect on what you've been doing and what you could do differently/try/better. Let your mind relax whilst you're doing this - it shouldn't be an intense process. The go back in and put your reflection into action.
It's important that you try to make adjustments to your performance, even if they fail. If you just do the same thing over and over again, you're missing the opportunity to diverge from your current behaviour, which is probably suboptimal given your experience.