You have to be okay with having uncomfortable talks with people if you are ever going to be able to have a real meaningful relationship. The fear of being uncomfortable should never outweigh the need to have a conversation. If you are afraid to talk about it, it probably means you really should talk about it.
1. Any conversation had while emotions are running wild is non-productive. If you or whoever you are talking with cant talk without yelling or being nasty take a break, calm down, and come back to it later.
2. When having a conversation i think it should be about presenting your perspective and feelings. Notice that i say conversation and not argument. I think arguments are not great and the word argument sounds like there will be a “winner”. That is just not how a relationship should work imo.
3. If you have trouble with this in your relationship, practice. Present small opportunities to bring up little issues even if everything feels fine. I call them “check ins” with my SO. It is a good opportunity to get comfortable talking about things we might otherwise struggle to find the time to bring up and it strengthens our communication skill. It also keeps resentment away because we handle everything immediately.
4. Communication is a skill. It is learned and it takes time and that is okay.
if you believe that, you miss a few decades of history in your knowledge ..
but then what's the point of arguing ? :)