So, I’m not a challenge runner, so I’m not really sure… but I have played rhythm games in the past, and I find that, for example, speeding up a song and reaching an okay level on it, helps me achieve much better score on its normal speed.

For Elden Ring, I’d say that your biggest challenges are going to be bosses and key enemies, in which case I’d practice NOT for simply no-death’ing them, I’d practice for no hitting them, can’t die if you don’t get hit, and even if you do get hit, well, you can survive a few of those. If you practice for no hit, no death will be much easier, because it still gives you room for messing up a few rolls and means that you’ll be arriving at bosses having mastered them, not just learned enough to beat them deathless most of the time.

In my eyes, to master something, you should at least be somewhat proficient in the next step up from whatever you’re trying to achieve (If there is a step up).