Go to EQ. Then if it is inconvenient to use EQ all the time or you don't want to for any reason then you will know where to go.

Also you could try listening to some frequency sweeps and see if you get any big treble peaks in your ears. These can be hard to EQ perfectly and if you have them you might be better off finding a set that doesn't produce them as much.

This is seriously important. No matter what the price range, whether an IEM works with your ears to produce a smooth response is far more important than what any reviewer says or the set's reputation for "technicalities". Most people seem to think the Aria is better than the Chu but for me the Chu is very good and the Aria is the worst thing I have ever heard.

But how to find the one that sounds best to you? Well that's hard. You can start by looking through various reviewer's databases and notice how they show different peaks at different magnitudes. If one reviewer's measurement of an IEM that you own shows treble spikes that correspond with what you hear in your ears then that might be an indication that that particular's measurements are more relevant to you than others'.

For example, I don't find Crinacle's measurements useful to me at all. Many of his measurements do not show treble spikes that I hear and that other reviewers' measurements pick up on. I particularly like Precogvision's measurement database. Most of his measurement's show nasty treble spikes above 10k but notably the Blessing 2: Dusk did not and most other measurements showed it as smooth as well so I bought that one and lo and behold, it sounds good to me. It has no flaws that I can't improve with EQ so it is total endgame for me.