Main task in the main display, docs and other references on the left display and email/messages on the right. Works wonderfully.
I’m so used to this setup that when I go to my real job and am constrained to a single monitor I feel like I’m looking through a periscope at my work.
I did that before switching to single display after having multiples from the first day of my career onwards. But I didn't even had to try. By the end, because of how my work and setup has evolved, the second display was switched off 99% of the time.
So when I have the choice I put the entire budget into an ever better single monitor, rather than splitting it.
With that being said, I ended up with 3 monitors in my apartment because I bought them incrementally across 3 years(though they're the same model). And also I play video games from time to time, for most of the games, it's better to have 3 monitors instead of an ultrawide one.
Then I upgraded to 3 displays, it's much better. Because I have an explicit main display.
So a viable way is, even with two displays, don't try to utilize them. Put the main one in the center, and pretend the other doesn't exist. Once you really want to use the other display, instead of for the sake of utilizing them only, you'll know it.