One classic sentence starter could be 'In the dead of night, a strange noise echoed through the empty house.' It immediately sets a spooky mood as the 'dead of night' implies a time when most people are asleep and vulnerable, and a strange noise in an empty house is often associated with something sinister.
A great starting sentence for a story might be 'The day began like any other, but little did I know...'. It creates a sense of normalcy at first and then hints at something unexpected to come. This type of start draws the reader in as they want to find out what that 'little did I know' part is all about.
Well, 'Long ago, in a different world...' is a great sentence starter for a story. It makes the reader think about a time and place that's not the present. 'Suddenly, everything changed...' is also good as it grabs the reader's attention right away, making them wonder what changed. 'There was a small town where...' is useful for setting the scene in a more specific location.
Some good sentence starters could be 'In the shadowy recesses of the old mansion, a strange silence prevailed...' or 'The howling wind whipped through the desolate graveyard as...' Another one could be 'Amidst the thick fog that cloaked the ancient forest, a figure emerged...'
A less common but effective starter could be 'The night was pitch - black, and the only sounds were the stealthy movements of the enemy troops...'. This builds suspense and mystery. Or 'From the trenches, where fear and hope coexisted in equal measure, a legend was about to be born...'. This gives a sense of the emotional state of the soldiers in the trenches and hints at an extraordinary story that is about to unfold.
One good sentence starter could be 'In a small town that time seemed to have forgotten...'. This immediately sets a scene that is often characteristic of realistic fiction. It gives a sense of place and a hint that there might be stories hidden within this forgotten - by - time location.