Well the same principles apply as when it comes to daps or iems. You can see the effect of cables as like covering a plastic sheet with a see through plastic sheet in a different color. You mix the different colors to create a new one. But the effects of cables are more subtle.
When I first started to listen to cables, I would just listen for a whole day or maybe two to a cable. Or maybe even a week, or two weeks. Don't try to analyze very analytically, just try to enjoy your music like usual, and listen to different types of music. And don't compare directly to the other cable, just try to get a feel of how the cable sounds. Then after a while when you are accustomed to the cable, switch to the other cable and play different music again. Often, some songs that you previously liked don't sound as good, but others might sound better with the other combo. Or one cable just generally sounds better. Then try to figure out what makes it sound better, is it because the sounds is warmer, more emotional? Then its possible there is more bass. Or is it because there is more detail in the music, more clarity? Then it might be more treble. In the beginning, just look for these large differences and see it as a puzzle. Don't put pressure on yourself to hear a difference instantly. It used to take me weeks to figure out a cable, and sometimes it still takes a while. But you break it down piece by piece.
If you would like to try a more analytical perspective, it is good to start with the bass. If a bass is more controlled, the stage will sound cleaner. It can also make the sound warmer or fuller, or on the other hand, less warm or leaner. So if a sound is cleaner, it is possible there is either more treble or less bass. Especially if the note size is smaller, the sound can be cleaner. This will happen if there is less bass for instance. But this is more advanced maybe, just start with the first part, listening for a long time. Don't rush it and pressure yourself. Then try to think about large differences, and after that smaller differences.