It is impossible to create the totally original plot with totally original characters.
That aside, in how we write, we write with a pattern in structure. For example, we all start at the beginning, we have a middle and we have an end.
SO where should a writer start?
1) Establish characters - Introduce them one at a time or in small groups. Now, this doesn't mean we start the story with pages of backstory. If you do that, you will be struck by lightning. Well, actually you won't. But, it's a really big pet peeve of mine and I'm sure 99% of your readers. The best way to introduce your characters is through your other characters. Don't force your characters on the reader, give us time to get to know them, but don't take too long either.
2) Establish place - This doesn't mean start with the weather and the city. But, place them somewhere and give brief glimpses into where that is so your reader can get a bearing.
3) Start the action - Set up the dramatic presence to the story. Raise the central question. If you're writing a mystery maybe start with a murder. Then the reader asks: Who did it? If it's literary fiction, give your readers a puzzle to ponder. In Citizen Kane it's "What's Rosebud?"
4) Start the story late - Stories should begin the moment they get off the ground. It gets the reader involved immediately.
5) Establish the tone - is it a comedy or a tragedy? Give us a feel for the style, is it witty or somber?
Source: Theme & Strategy