I think that communication is important as it acts like a bond between people. If we can't communicate, we cannot understand each other, which can occasionally lead to misunderstanding.
My favourite form of communication is speech as it lets us communicate without much trouble.
I decide which form of communication to use by looking at the situation. If my friend is overseas, I would write to him to greet him. If there were two friends fighting, I would try to talk to them to stop them from fighting. If that doesn't help, I would try to break them apart.
The only difficulty that I face in communicating with others is when there is too many people speaking at the same time and I could not get their attention.