I also struggle with it personally, I reckon it willl come with time:)

Try to imagine the instruments in your face if you are using headphones. For example, the open ones I feel the sound almost on my ears, while the closed ones on my nose. Works for me, hope it helps

Warm up your ears using the Practice mode on the right. This helps me a lot getting a feeling for the difference.

Do you have monitors, or only headphones? Even if you mix exclusively on phones, it helps with stereo image to use ANY monitors, no matter how good or bad they and your room are, for panning
Tone makes no difference to the stereo image -unless something is VERY wrong.

Make sure your computer sound and browser are set to stereo, and that your headphones are stereo.

i struggled a long time with this too. Until i switched back to monitors.
I got the tip here to close my eyes and try to imagine the head/guitar/sound source to the left or the right of the center.
Once i did these things, i increased in lvl in no time.

Thanks all - I will give it a go with monitors as well. I had thought that it would definitely be easier with headphones but maybe not for this one.

Hi !

In my case, before the exercise I straighten up and try to visualize the stereo field as a rectangular band in front of my head, then, and in most exercices, I close my eyes and listen very closely. I also try to set some reference points at 0,3 / 0,5 / 0,7 , when those are known, most of the time you'll achieve this kind of stereo exercises without any struggle, and so you'll be able to hear the stereo differences in any tracks !

You can also add a stereo exercise to your daily routine and do not stop it until you have gained a level in this exercise !
I hope it will help you !
btw i'm using beyerdynamics headphones and never got any problem

The exercise is for stereo panning I believe, where as headphones are technically binaural and not strictly stereo, as there's no bleed from left to right ear and right to left ear.

This changes how you perceive the stereo field and things that are hard panned left, instead of being at a 45 degree angle Infront of you, will be at around 90 deg, off directly to the side. Also things either not hard panned, nor mono will be much harder to locate correctly as they will appear to come from around your head, rather than from somewhere in front of you across roughly 45 deg between the speakers. This can make it much harder to correctly place things where they would be in a stereo field, and is one of the reasons why most engineers will mix on monitors. ;)