Public speaking tip – grabbing audience attention

 
And the first part of any speech or presentation is to gain that attention – arouse it, focus it and keep it.
Don’t waste your breath on the expected or the blah.
If you must begin with something like “Good evening”, then make it different, or unusual. Here in Australia, we might say “G’day!” That would be unexpected.
Otherwise use your voice and body language to make the greeting unusual, challenging, noticeable.
Use pause here.
Then use an opening that grabs the attention.
You can use a question, a joke, a comment about the people or surroundings or event.
You can make a statement, use a quotation, or simply use body language or gesture. But choose that opening to grab attention, to align with the audience and their needs, hopes and aspirations, and to lead into your message.