1. Be concise and to the point, because you don't need clues to know what your friend is saying.
2. Answer all questions, and think if you can answer further questions, this tip is for the clueless because some people just give information to other people.
3. Use proper spelling, grammar & punctuation, People are not robots but you still need to know how to spell.
4. Make it personal, actually try to make it a part of you.
5. Use templates for frequently used responses, search online for something new to say.