One of the important ways of having difficult or uncomfortable conversations is considering the same situation but from the point of view of others. Sometimes, we think that the solution to the problem only depends on our happiness and what we want. We often dont want to think about what the other person may have in mind. So, before having a conversation, it's better to prepare for it and try to find a way to benefit both parties.

In my opinion, a difficult conversation may also involve listening to the other person. If you are having a conflict with someone, it is likely that you dont want to hear anything from them. But at the same time, there should a level of flexibility in your discussion that shows that you really want to solve a problem instead of fighting with them. Hence, work on your listening skills before having difficult conversations.

Doing these things are pretty much easier said than done. You may want to end the conversation in the middle and make the matter much worse. Alternatively, you can be patient and built sufficient strength to just survive the whole time by any means. Have faith in mind that good days will come soon and your life is much more important and beautiful than this day. That's one of the effective ways of going through this tough phase and keeping your act together without losing yourself.

 These days I am taking a suicide prevention training along with a course on Dot listening and that has taught me a lot about what you can do for the other person when they are suffering from something. More often than not, we feel the need to rescue another person, especially the empaths amongst us. If someone vents out to us or cries in front of us, we feel a sort of obligation to make them smile and forget that they were sad. But I am sorry to tell you that these things and this approach might not be effective, and I am saying that more to myself than anyone else. The only thing a person who is suffering need you to do is listen to them and help them explore the feelings that they are not knotted in. Yes you may feel the need to provide solutions, but believe me they have gone through everything. 
On that note, if you are writing to them, tell them that you will have the space to hear them out without any judgement, whenever need be. It will have a much better impact than anything else.