Point of View  
Point of view refers to the character through whom the story is told.  Most of Treasure Island features a first person narrator, Jim Hawkins. But for chapters XVI-XVIII, the story is narrated by Dr. Livesey. The author switches briefly to the doctor's point of view because there are events taking place that Jim, who is hiding on the island, is unaware of. A story told in the first person ("I") can only tell of action that is witnessed directly by the narrator. In a story in which events take place simultaneously in two places (as is the case here), the narrator cannot possibly know about both, so an alternative form of narration is required.

An alternative strategy for the author would have been for the doctor to have explained all the events to Jim on Jim's return to the loghouse. But this would have been a clumsy way of telling the story, and Stevenson wisely switches narrator when the situation  calls for it.

Story-telling 
Treasure Island is a model of good story-telling. From the outset, it creates interest and suspense, and the story never flags. The characterization is always vivid. In just a few lines, Stevenson gives the reader a detailed word picture of each man being described. On the first page, for example, this is the description of the old seaman, Billy Bones:

A tall, strong, heavy, nut-brown man; his tarry pigtail falling over the shoulders of his soiled blue coat; his hands ragged and scarred, with black, broken nails; and the saber cut across own cheek, a dirty livid white.

All the adjectives are well chosen and they make it easy to visualize this decrepit old pirate. The same applies to the descriptions of every character in the novel.

Another notable feature of Treasure Island is that the language is always appropriate for the speaker. The educated speech of the doctor and the squire is contrasted with that of the pirates, who speak in slang and use ungrammatical expressions. The best example is Long John Silver, who speaks a language all his own, with repeated idiosyncratic phrases such as "you may lay to that" (meaning "you can be sure of that"). The language he uses becomes part of his distinct identity.

In short, Treasure Island might be used as a textbook for an aspiring creative writer, so well does Stevenson use the basic elements that make up a good story: a strong plot, well-drawn, distinct characters, believable dialogue, and effective setting. The setting is where the story takes place. Whether it is the tavern at Bristol, or the treasure island, Stevenson creates a clear picture of it in the reader's mind with a few deft sentences.