In general, I start with comparing my score to the high scores on a game. A good game for me tends to be about half of what excellent players can score. You’ll start to get a sense of where you tend to net out over time.
If I easily score close to or above the top scores, I assume they’ve recently been reset, so I then look at how far I’m progressing in a game. Did I light up most of the playfield? Did I repeatedly start multi-ball? On EMs, did I play for s significant length of time? Did I hit things I was aiming at?
There’s an app, Pindigo, which you can use to track your high scores and it will compare them to other people, but it depends how many people record scores—a couple of times my scores were #1 or #2 and I *know* it’s impossible that those scores are anywhere near the best simply bc even the high scores on the machine were already way higher.
I’ve gotten good enough that once in a very rare while, a high score of mine is truly a high score. That’s a great feeling! Good luck!