I have many types of eartips, 20+. w1,omni,100+, velvet,velvet wide bore, baroque, s&s, sencai, fh18, xelastec, vivid, etc etcmy problem is that with my right ear they are all problematic due to irritation, they only differ in degree. it's just that this constant changing and testing is boring, it's been going on for months... I have a high-end stereo system and a headphone system, I just turn it on and it works without any anomalies, irritations or frustrating feelings... I think my iem system should receive less attention because it's simply not worth it..
You have to persevere with trial and error based on common sense testing of tips that are different in a way that seems to be beneficial to your fit needs. That is tips that are a step in the right direction based on whatever trend emerges in terms of beneficial shape etc versus just trying any old random tip types hoping for the best.
Even seemingly very similar tips can behave quite differently in terms of comfort over extended use and even the same tips can give different fit and comfort results when used on IEM with different dimensions, angles etc. subtle shape, diameter and material differences can matter a lot if the IEM are a problematic fit for you in some way.
On my most used sets I have settled on KBear07 tips. These three IEM are all from AuR Audio and share quite similar shape and nozzle angles and for me have the same tip requirements. Two other IEM have different shapes and nozzle lengths and I need different tips on both for a comfortable and effective fit.
I have found that even the cable used can alter the comfort, it seems to be associated with the ear hook shape and stiffness and how that may pull on the IEM in your ear. Sometimes reshaping the ear hook makes a significant difference to long term comfort.
Unfortunately it is something that only you can work on and figure out.
The trying and testing process itself I find complicates fit assessment because changing and inserting frequently can be irritating which causes a problem in and of itself. As does simply being aware of the fit because you are experimenting. I think it is best to get a tips that seem promising and just use them for a bit and see how they work out over a few hours or so of casual listening while doing something else so you are less aware. If you are a bit frustrated with it you are probably better to stop even listening with the IEM for a few days then come back to them trying just one set of tips at a time.
Of course there is the problem that some IEM simply may not fit you well and no amount of tip experimenting will fix that completely.
Of course giving up on IEM altogether saves a lot of dicking around if you are getting nowhere and don’t have a particular need or desire to use IEM.