Hi, I would like someone to help me with a project I have to do for university. I have to make a presentation on the do'S and don'ts in business invitations. What I mainly want to talk about is when you send letters to customers or to

hi ,everybody i wrote an invitation letter for a very importmant conference last week but i don't know much about how to write an excellent business letter,would you please give me some valuable comments? whatever you are ,thank you very much