Your first message should be written in the same tone you would use in person.
The reader should be able to tell you are friendly; just keep it casual and polite.
You have a stronger chance of getting a speedy response.
Special Subject Line Crappy openers like ‘Hi there’ or ‘Hi Gorgeous’ are clichéd and most likely to get yawned over and forgotten quickly.
If you have a sense of humor, laughter almost always works in your favor.