A sentence starts out like...

A sentence starts out as a thought. The thought first enters your mind and then you formulate it into words that might help others understand where you're coming from. It starts out with this thought and then you add descriptive words so that the imagery can entice the reader and make them feel exactly as you do. A sentence starts out with almost no effort; as we formulate words and conversation as we think most of the time. It is just second nature to humans to formulate a sentence based on their thoughts. It may be difficult when you begin the sentence if the subject is difficult to describe or if the subject is one that strikes up emotion. There is no specific way that a sentence starts because sentences are provoked by many different occurrences or emotions.