Communication is important as it helps as get along with other people. Imagine a world without knowing anyone or being able to talk to anyone, we would not only be lonely but we would not receive help when we need it as would not be able to ask for help without communicating.
My favorite form of communication is using instant messengers because they are able to communicate with people faraway without paying any money unlike calling or smsing and the other party will be notified and can reply immediately.
I would decide on the form of communication based on the situation. If its important, i would call the person, if its less serious, i would sms or email him.
The difficulties i face when communicating with other people is either the person does not reply or answer or i am nervous to communicate with people i do not know well.